Imagine the argument is a bridge between premises and conclusion.

1. SA is like building an entire bridge. If you drop it in, the conclusion must follow.

2. NA is like identifying the foundation pillar that’s holding the bridge up.

If you remove that pillar → bridge (argument) collapses.

Argument:

All current domestic mammals = domesticated long ago.

People have tried since, and failed to domesticate others.

Conclusion: Most of today’s wild large mammals are either hard to domesticate or not worth it.

Key move:

The argument assumes that past failures are still relevant now.

NA Test (Negation):

Try negating (B): “It is much easier today to domesticate wild large mammals.”

What happens?

Then past failures are irrelevant to the present = the argument falls apart.

So (B) is necessary. It keeps the logic of the argument alive.

But does it guarantee the conclusion? Nope. Maybe it's still hard, but not most are. Maybe values have changed, etc.

SA Test:

Now ask: Would (B) be enough, by itself, to prove the conclusion?

No. Even if it’s not easier now, that doesn't prove that most species today are hard to domesticate or not worth it.

We’d still need more, like actual confirmation of their worth or traits.

So (B) isn’t sufficient.

Here (B) in as an SA

“If most wild large mammal species in existence today were worth domesticating and not difficult to domesticate, people would have succeeded in domesticating them in the past.”

Why this works:

Contrapositive: If people didn’t succeed in domesticating them in the past (which they didn’t),

then → they are either not worth it or too hard to domesticate now.

That’s your conclusion, guaranteed.

For causal chain arguments like these, a common pattern is:

1. There’s a causal premise that SEEMS disconnected from the conclusion.

Example: Anti-inflammatory drugs reduce cognitive deterioration.

But… how does that relate to microglia causing Alzheimer's?

2. The correct answer will often bridge that gap.

Example: (B) says anti-inflammatory drugs reduce microglia production.

So YES, in 90% of these causal chain questions, the right answer links an isolated causal element back to the main argument.

Blind review = PROVING your answer, NOT finding a new one.

Your goal is to confirm, not change.

If you can prove your first answer is correct, you keep it.

If you can’t prove it, THEN you find the one you can prove.

You don’t need a "better" answer. You need a "provable" answer.

Approach every review with:

“Can I prove this is right?” → If yes, keep it.

“Can I prove another answer is better?” → If yes, switch.

“Am I just doubting myself?” → Stop overthinking and trust your process.

This way, you’re actively building confidence in your reasoning, not just switching answers out of doubt.

Blind review = PROVING your answer, NOT finding a new one.

Your goal is to confirm, not change.

If you can prove your first answer is correct, you keep it.

If you can’t prove it, THEN you find the one you can prove.

You don’t need a "better" answer. You need a "provable" answer.

Approach every review with:

“Can I prove this is right?” → If yes, keep it.

“Can I prove another answer is better?” → If yes, switch.

“Am I just doubting myself?” → Stop overthinking and trust your process.

This way, you’re actively building confidence in your reasoning, not just switching answers out of doubt.

I think it's a potential chronology gap, just because the bird population increased after the mild winter doesn’t necessarily mean it remained higher throughout the year.

Would this be a valid gap to identify? Yes, but with an important distinction:

1. If this were a Weaken question, this could be a great angle to attack the argument.

2.However, in a Strengthen question, we’re looking for ways to reinforce the idea that the mild winter was responsible for a sustained increase in population.

Read Like a Lawyer, Not a Skimmer - Has worked for me on LR and RC.

It’s not about reading faster, it’s about reading right the first time.

1. Slow down on the stimulus, speed up on eliminating bad answers

2. Practice active reading (label Premise/Conclusion)

Do a 5-Second Mental “Pause” After Reading the Stimulus

What is this argument really saying? (Summarize it in one sentence)

What type of reasoning is being used? (Cause & Effect? Correlation? Comparison?)

What would help or hurt this reasoning?

Engage, engage, engage. Those words are there for a reason, especially for these type of questions.

Forget about assumptions and you'll be fine. If you still don't get it, respond and I'll add more to help you.

Forget the conclusion too, you're adding to the premise. Add a premise to the premise and see if the conclusion will still follow through (will it weaken or strengthen).

Weaken

Introduces an alternative cause

Shows the effect happens without the proposed cause

Shows the effect happens without the cause at the same rate

Suggests reverse causation

Shows the experiment was flawed

Strengthen

Rules out alternative causes

Shows the effect happens when the cause is present

Shows the effect is less likely when the cause is absent

Shows the cause actually precedes the effect

Shows the experiment was well-designed

For this example, correct answer is B. Why?

Strengthen Strategy: Make the Argument More Like an Ideal Experiment

(B) is correct because it shows that when the heavy metals are absent, the bacteria do NOT develop antibiotic resistance.

This rules out alternative explanations (like something else in the sewage causing resistance) and makes it much more likely that heavy metals are the cause of antibiotic resistance.

Why (B) Strengthens the Argument:

The argument claims that heavy-metal exposure promotes antibiotic resistance.

(B) shows that when bacteria are in similar sewage without heavy metals, they don’t develop either resistance.

This makes it clear that something about heavy metals is driving the change, rather than some other factor in the sewage.

This is a classic Strengthen via an Ideal Experiment answer: it isolates the variable (heavy metals) and shows that when it’s absent, the effect doesn’t happen!

Forget about assumptions and you'll be fine. If you still don't get it, respond and I'll add more to help you.

Forget the conclusion too, you're adding to the premise.

Weaken

Introduces an alternative cause

Shows the effect happens without the proposed cause

Shows the effect happens without the cause at the same rate

Suggests reverse causation

Shows the experiment was flawed

Strengthen

Rules out alternative causes

Shows the effect happens when the cause is present

Shows the effect is less likely when the cause is absent

Shows the cause actually precedes the effect

Shows the experiment was well-designed

For this example, correct answer is B. Why?

Strengthen Strategy: Make the Argument More Like an Ideal Experiment

(B) is correct because it shows that when the heavy metals are absent, the bacteria do NOT develop antibiotic resistance.

This rules out alternative explanations (like something else in the sewage causing resistance) and makes it much more likely that heavy metals are the cause of antibiotic resistance.

Why (B) Strengthens the Argument:

The argument claims that heavy-metal exposure promotes antibiotic resistance.

(B) shows that when bacteria are in similar sewage without heavy metals, they don’t develop either resistance.

This makes it clear that something about heavy metals is driving the change, rather than some other factor in the sewage.

This is a classic Strengthen via an Ideal Experiment answer: it isolates the variable (heavy metals) and shows that when it’s absent, the effect doesn’t happen!

Forget about assumptions and you'll be fine. If you still don't get it, respond and I'll add more to help you.

Fast Approach without diagramming

1. Spot the Key Shift in the Passage

You noticed “However”—that signals a contradiction or problem. Something went wrong.

The first part of the passage tells us that most large nurseries only sell disease-free plants.

But then Wally’s shipment had a virus. That’s the failure.

What Does This Mean?

The promise was that large nurseries sell only disease-free plants.

If Wally’s is a large nursery, it should have guaranteed its plants were disease-free.

But Johnson’s shipment had a virus, so Wally’s probably didn’t follow through on that guarantee.

What Kind of Answer Are We Looking For?

Something that confirms that a large nursery (if Wally’s is one) did NOT live up to expectations.

Look for an answer that connects Wally’s being a large nursery to the failure.

Find the Best Answer Choice

(E) says:

“If Wally’s Plants is a large nursery, then the raspberry plants that Johnson received were probably not entirely as they were guaranteed to be.”

This matches exactly!

“If Wally’s is large” → Then its plants were probably not as guaranteed (because they had a virus).

Try the method I shared above, you won't need to remember all that.

Fast Approach without diagramming

1. Spot the Key Shift in the Passage

You noticed "However"—that signals a contradiction or problem. Something went wrong.

The first part of the passage tells us that most large nurseries only sell disease-free plants.

But then Wally’s shipment had a virus. That’s the failure.

What Does This Mean?

The promise was that large nurseries sell only disease-free plants.

If Wally’s is a large nursery, it should have guaranteed its plants were disease-free.

But Johnson’s shipment had a virus, so Wally’s probably didn’t follow through on that guarantee.

2. What Kind of Answer Are We Looking For?

Something that confirms that a large nursery (if Wally’s is one) did NOT live up to expectations.

Look for an answer that connects Wally’s being a large nursery to the failure.

3. Find the Best Answer Choice

(E) says:

"If Wally's Plants is a large nursery, then the raspberry plants that Johnson received were probably not entirely as they were guaranteed to be."

This matches exactly!

"If Wally’s is large" → Then its plants were probably not as guaranteed (because they had a virus).

Fast approach w/ no diagramming.

Step 1: Identify the Key Conditional Rules

The stimulus contains two main conditions regarding where a Frequent Viewers club member can receive their discount coupon:

If a member rented more than 10 videos in the past month →

They can only receive the coupon at the last VideoKing location where they rented a movie.

If a member did NOT rent more than 10 videos in the past month →

They can only receive the coupon at the Main Street location.

Then, we are given a specific fact about Pat:

Pat has not rented more than 10 videos in the past month.

But Pat can receive the coupon at the Walnut Lane location.

Step 2: Identify the Contradiction, there's clearly one.

From Fact 2, we know that anyone who rented 10 or fewer videos should ONLY be able to get the coupon at Main Street.

But Pat, who rented 10 or fewer videos, is getting the coupon at Walnut Lane instead.

This violates the rule that such members can only get the coupon at Main Street.

Step 3: The Must Be True Inference

Since Pat’s case contradicts the second rule, the only possible explanation is that the second rule does not always hold.

There must be at least one exception to the rule that members who rented 10 or fewer videos can only receive the coupon at Main Street.

What to Look for in the Answer Choices

The answer choice should express the idea that there is an exception to the rule that members who rented 10 or fewer videos must only go to Main Street.

It might also highlight that Walnut Lane is an additional or alternative location for these members.

(D) "Some people who are not members of the Frequent Viewers club can receive the special discount coupon."

Now, think logically:

The rules only apply to members.

But Pat is violating the stated rule (should have been at Main Street, but instead is at Walnut Lane).

If there's an exception for a club member, could there be exceptions for non-members? Yes!

This is the strongest inference because it shows that the club membership rules are not absolute.

By focusing on the contradiction and thinking through the logical implications, you can arrive at the correct MBT answer without needing a diagram!

Fast approach w/ no diagramming

You must ignore the background information (statements about coffeehouses and restaurants). The only two conditional rules that matter are:

1. If a public place is uncomfortable, then it is NOT well-designed.

2. All comfortable public places have spacious interiors.

Both statements mention comfortable/uncomfortable, so that’s the bridge between them. Now, I strike them out. Notice how I didn’t even bother to diagram or mention contrapositives? Let’s keep going…

By striking the connection, both remaining parts of the statements are now on the necessary side, meaning they are both “then” statements. You cannot connect two necessary conditions directly, so you need to flip one to its contrapositive.

I choose to flip “NOT well-designed” from the NC side to the SC side. That means I have to take the contrapositive, so the “NOT” part? Lose it!

Now, you have: If well-designed, then… (now just plug in the other half that remained on the NC side without changing anything).

Final result: If well-designed, then spacious interior.

Now, go find that answer!

Problem with C

Break Down Answer Choice (C)

Answer (C): All public places that feature artwork are well-designed.

This is not necessarily true because nowhere in the stimulus does it say that all public places that feature artwork must be well-designed.

What do we know about artwork? The only relevant statement in the stimulus that mentions artwork is:

Most well-designed public places feature artwork.

Why (C) is Incorrect

Most ≠ All

The stimulus only says that most well-designed places feature artwork.

But (C) flips it and says all places that feature artwork are well-designed.

That’s incorrect logic because "most" doesn’t allow us to conclude "all."

No Direct Link from Artwork to Well-Designed

The stimulus tells us that most well-designed places feature artwork, but it never says that featuring artwork guarantees that a place is well-designed.

(C) tries to claim a rule that does not exist in the stimulus.

You must ignore the background information (statements about coffeehouses and restaurants). The only two conditional rules that matter are:

1. If a public place is uncomfortable, then it is NOT well-designed.

2. All comfortable public places have spacious interiors.

Both statements mention comfortable/uncomfortable, so that’s the bridge between them. Now, I strike them out. Notice how I didn’t even bother to diagram or mention contrapositives? Let’s keep going…

By striking the connection, both remaining parts of the statements are now on the necessary side, meaning they are both “then” statements. You cannot connect two necessary conditions directly, so you need to flip one to its contrapositive.

I choose to flip “NOT well-designed” from the NC side to the SC side. That means I have to take the contrapositive, so the “NOT” part? Lose it!

Now, you have: If well-designed, then… (now just plug in the other half that remained on the NC side without changing anything).

Final result: If well-designed, then spacious interior.

Now, go find that answer!

Problem with C

Break Down Answer Choice (C)

Answer (C): All public places that feature artwork are well-designed.

This is not necessarily true because nowhere in the stimulus does it say that all public places that feature artwork must be well-designed.

What do we know about artwork? The only relevant statement in the stimulus that mentions artwork is:

Most well-designed public places feature artwork.

Why (C) is Incorrect

Most ≠ All

The stimulus only says that most well-designed places feature artwork.

But (C) flips it and says all places that feature artwork are well-designed.

That’s incorrect logic because "most" doesn’t allow us to conclude "all."

No Direct Link from Artwork to Well-Designed

The stimulus tells us that most well-designed places feature artwork, but it never says that featuring artwork guarantees that a place is well-designed.

(C) tries to claim a rule that does not exist in the stimulus.

You must ignore the background information (statements about coffeehouses and restaurants). The only two conditional rules that matter are:

1. If a public place is uncomfortable, then it is NOT well-designed.

2. All comfortable public places have spacious interiors.

Both statements mention comfortable/uncomfortable, so that’s the bridge between them. Now, I strike them out. Notice how I didn’t even bother to diagram or mention contrapositives? Let’s keep going…

By striking the connection, both remaining parts of the statements are now on the necessary side, meaning they are both “then” statements. You cannot connect two necessary conditions directly, so you need to flip one to its contrapositive.

I choose to flip “NOT well-designed” from the NC side to the SC side. That means I have to take the contrapositive, so the “NOT” part? Lose it!

Now, you have: If well-designed, then… (now just plug in the other half that remained on the NC side without changing anything).

Final result: If well-designed, then spacious interior.

Now, go find that answer!

You must ignore the background information (statements about coffeehouses and restaurants). The only two conditional rules that matter are:

1. If a public place is uncomfortable, then it is NOT well-designed.

2. All comfortable public places have spacious interiors.

Both statements mention comfortable/uncomfortable, so that’s the bridge between them. Now, I strike them out. Notice how I didn’t even bother to diagram or mention contrapositives? Let’s keep going...

By striking the connection, both remaining parts of the statements are now on the necessary side, meaning they are both "then" statements. You cannot connect two necessary conditions directly, so you need to flip one to its contrapositive.

I choose to flip "NOT well-designed" from the NC side to the SC side. That means I have to take the contrapositive, so the "NOT" part? Lose it!

Now, you have: If well-designed, then... (now just plug in the other half that remained on the NC side without changing anything).

Final result: If well-designed, then spacious interior.

Now, go find that answer!

I did the following, simply using pure logic to answer this question and forget about diagramming.

1. I recognized that there are two conditional statements.

Fact 1: If a pet store sells Tropical Fish but NOT Exotic Birds, then it must sell Gerbils.

This means selling that combo (Tropical Fish & NOT Birds) guarantees Gerbils.

Fact 2: NO independent pet store sells Gerbils.

This means that if a store is independent, it CANNOT sell Gerbils.

2. I decides to join the two statements to come up with a logical conclusion or MBT

How did I do that? Well...follow along.

I started with the strongest statement, Fact 2: (I see the "no" which makes it the strongest statement. I also know that no is from group 4, so negate necessary assumption).

So if independent pet store then (stop here, this is where you join it with fact 1). How? CONTRAPOSITIVE!

That means I have to take from the sufficient side of statement 1 so that I can make a contrapositive for the then part above, which is my NC side. I can't take from the NC side of the first statement to make a contrastive for a NC.

What does that mean?

Fact 2 If a pet store sells TF but NOT EB then it must sell Gs. Forget about the the must sell Gs part, I don't care about the NC part, I can't take from the NC part to make a contrastive for the NC part, I must take from the SC part.

So going back to the SC that I already made earlier, Fact 2: if independent pet store (SC) then Fact 1: Not a pet store that sells TP or birds. (I have to put the not there, that's just the rule of negating. Also the not exotic bird must change to just birds. It moved from one side to another).

This simply put is:

Fact 1. If a pet store sells Tropical Fish but NOT Exotic Birds, then it must sell Gerbils.

Fact 2: NO independent pet store sells Gerbils.

Join them: by first striking what they have in common. What are you left with? Two sufficient conditional statements, but wait a minute, I can't have 2 SC statements. Now what? Contrapositive the one. Oh yeah well... Take the strong statement (fact 2, drop the no for now, no is group 4 so save it for NC side)

If independent pet store then (contrapositive statement 1) and (bring back the no you saved for NC side) not a pet store that sells TF (but and and is the same thing, here you're on the contrapositive side so change it to or) or EB (what happened to the not you ask? contrapositive, lose it!)

Now you're left with if independent pet store then not a pet store that sells TB or EB.

Now do you see the answer "No independently owned pet store sells tropical fish but not exotic birds."??

If not just look at this: No independent pet store sells tropical fish but NOT exotic birds.

This means:

If a store is independent, then it cannot sell TF while NOT selling EB.

This is just me thinking out loud. I hope it helps!