This question stem here says, which one of the following of true most seriously weakens argument?

So we are told that there is an argument up here.

And one of these answer choices, if it's true, will weaken this argument.

So with the knowledge that this is an argument here,

the first thing we need to do is identify the premises and the conclusion.

That way we understand in what space we're supposed to get into.

Because to weaken an argument, you have to get into that space between the premise and conclusion.

Making it so that even if the premises are true, we have now more reason to think the conclusion not true.

That's what it means to weaken.

A cup of raw milk, after being heated in a microwave to 50 degrees Celsius,

contains half its original concentration, initial concentration, of a particular enzyme, the lysozyme.

Whatever that is.

Whatever that is, it used to have 100 units of it, now it has 50 units of it.

If, however, the milk reaches the temperature through exposure to conventional heat source.

What is a conventional heat source?

Like a fire.

Of 50 degrees Celsius, it will contain nearly all of its initial concentration enzyme, of the enzyme.

Referential phrasing referring to the same enzyme, lysozyme.

So therefore, and here's our conclusion indicator, therefore, this is the conclusion, these are the premises.

This is reading like a phenomenon hypothesis type question, like a causation type question.

They're about to give us a hypothesis that is causal in nature.

The phenomenon is this, they just described it.

A cup of milk, if you put it in the microwave, and then another cup of milk, put it on the stove,

cook it to 50 degrees Celsius, one of them comes out with half of its lysozyme,

the other one comes out with all of its lysozyme.

Why?

Why is that weird?

We need to explain that.

We need to come up with a hypothesis that explains this phenomenon.

So what is it?

It's saying, well, what destroys the enzyme is not heat, but microwaves, which generate heat.

I guess that makes sense, right?

Because how else do you explain that it came out with half of its lysozyme?

How well does this phenomenon support this hypothesis?

This seems like a credible hypothesis, believable at least.

But I don't know, there could be other hypotheses.

Other explanations, other causal explanations for this effect, for this phenomenon.

So let's read the answer choices here.

destroys nearly all the lysozyme initially present in that milk.

See, A is very tempting because they said, look, what destroys the enzyme is not heat,

but rather its microwaves, which generate the heat.

A seems to say, well, but if the temperature goes up, more of the lysozyme is destroyed. Isn't that heat then?

Isn't that heat? Doesn't that weaken this argument?

Doesn't that mean it is heat?

But you see, where is this heat coming from?

It's still coming from the microwave.

So if we heat it up to 100 degrees, we still don't know whether it's heat or if it's the microwave.

It could still be because it's being exposed to more microwaves now also.

So it really could still be the microwave that's destroying the enzyme.

That's why A doesn't work.

A doesn't say that it's not.

Or A doesn't make us think that it's not.

Answer choice A is just as consistent with it being microwaves that's destroying lysozyme.

These enzymes can be replaced by adding enzymes that have been extracted from other sources.

Well, that's great.

I mean, if you're drinking your milk and you're short on lysozyme for your bodily health,

then this is great for you.

You can just extract some lysozyme and just pour it into your milk

and you'll have lysozyme-reinforced milk.

But I don't see how that has anything to do with our argument.

will reach that temperature more slowly than it would if exposed to a conventional heat source

that is hotter than 50 degrees.

So this is a comparative statement.

More slowly.

What will be more slowly than what?

Well, here we go.

A liquid exposed to a conventional heat source of exactly 50 degrees

to reach that temperature of 50 degrees from just say a conventional oven.

You set the fire on your stove, let's say.

Not oven, stove.

You set the fire on your stove such that it's exactly 50 degrees.

It's not even possible.

Fire burns hotter than...

Okay, fine. We'll have to go with oven then.

Or your hot plate. Let's say your hot plate.

You set your hot plate to exactly 50 degrees and then you put a pot of water on it

and you count the amount of time it takes for that liquid to reach 50 degrees.

Now whatever that time is, you call it x, you compare it to this other time,

which is you take a pot of water and then you put it on a hot stove again,

but this time the hot stove is 70 degrees.

It's hotter than 50 degrees, 70 degrees.

And you call this time y.

And what they're saying is that x will be a longer time than y.

x will be 5 minutes, y will be 3 minutes.

But what does that have to do with anything?

We're trying to compare about microwaves.

We're trying to say that this explanation, that it's not the heat,

but rather the microwaves that are destroying the lysozymes,

that this explanation doesn't follow.

And this is just like talking about something totally...

This is just like B. It's totally irrelevant.

from milk that's been briefly heated by exposure to...

I mean, again, like who cares?

We don't care about the taste being different.

How does the taste being different tell us whether it's the heat or the microwave?

Or rather, how does that in any way convince us that it's not the microwaves

that's destroying the lysozymes?

Are you presuming that you can taste the lysozymes?

And therefore, if you don't taste...

If it doesn't noticeably taste different to you, that what?

That the lysozymes are therefore present in the same concentration?

See, because that's wrong.

That's you're not accepting their premises.

They're already telling you.

We already know that it comes out with half the lysozymes.

So if you can't taste it, that shows nothing.

It still has half the lysozymes.

You just can't taste lysozyme very well.

That's all D does.

So it really doesn't help or help us answer this question,

help us accomplish our task of weakening this argument at all.

that are much hotter than the overall temperature that liquid will ultimately reach.

There you go.

See, E is very, very subtle, but it's the right answer choice.

Heating a liquid by microwave, which is what we're doing here,

creates little zones that are much hotter than the overall temperature.

What is the overall temperature of this milk?

The overall temperature is 50.

So they're saying little pockets inside the milk.

Let's imagine this is the thing containing the milk.

They're saying this pocket, this pocket, this pocket, this pocket, this pocket, and this pocket.

They're way above, say, 100 degrees.

They're like 150 degrees.

All the things that are outside the circle are at like, I don't know, 30 degrees.

Then they kind of mix this together, and that's how it cools.

Now that gives us reason to think that perhaps it is the heat after all

and has nothing to do with the microwaves.

Perhaps it's within these pockets that the lysozyme is being completely destroyed,

and therefore what remains, there's no purple is lysozyme-free zones.

They've been destroyed because it's 150 degrees Celsius in there.

So now we think that even though despite the fact that they come out to about 50 degrees

at the end of it because it averages out,

now I have less reason to think that it's the microwave and not the heat.

Instead, it actually is the heat.

In other words, I think now if I burn this milk to 150 degrees,

even on my stovetop, it'll still lose its lysozymes.

Because previously when we thought the temperature was held constant,

yeah, that is a good conclusion to draw.

It's not the heat because how could it be the heat?

The heat is held constant, so it's probably the microwaves.

But now we know that even though the milk comes out to 50 degrees from a microwave,

this 50 degrees is only speaking to the average temperature of the milk.

In the process, parts of the milk got heated way hotter than 50 degrees.

At this point, now I can't draw this conclusion.

At this point, it becomes highly suspect that in fact it is heat and not the microwaves.

So that's how we effectively weaken an argument.