PT72.S2.Q2 - Sumerians and irrigation

CRLSUUUU

For this question: https://7sage.com/lsat_explanations/lsat-72-section-2-question-02/

Why can’t B be correct? The stimulus just says toxic levels, then collapse, suggesting toxic levels are what caused the collapse, but it could just be a coincidence. Something else unrelated to the toxic levels is the cause of collapse (aka would have collapsed sooner or later even without use of irrigation). And so if we expose this gap, can’t we say well if it’s not the irrigation that caused the collapse how can we say irrigation would cause collapse in modern society?

Admin note: edited title; please use the format of "PT#.S#.Q# - [brief description]"

Little Grasshopper

Let me help you and will go through the answer choices together.

It is weakening question. The conclusion is stating that a similar fate likely to happen if they rely heavily rely on irrigation. Let's start with the main premise where it starts with the word But, says that toxic levels build up after the water evaporates. We can destroy this argument fairly easily.I focus on the conclusion and the main premise that has the word "But"

Let's diagram:

Premise with But: Water Evaporates--> Soil becomes toxic.

Conclusion : Similar fate with Modern society--> dependent on irrigation

We want to negate the main premise and flip it around.

We negated the Not Soil becomes toxic ---> Not Water Evaporates.

Watch out for context traps. The LSAT writers will get on you on the context and love nailing people that get wrapped up in context.

Let's look at the answer choices:
Answer choice A strengthens the argument and does the opposite. It is out.

Answer choice B is context and doesn't tell how modern civil would collapse by relying on heavy irrigation. It is wrong

Answer choice C does weaken the argument because it states that modern society has techniques that protect the soil from becoming toxic when the water evaporates. This is the winner.

Answer choice D it is out of scope because Modern society does rely on irrigation.

Answer choice E is just like b and doesn't tell how modern society would collapse relying irrigation. It is wrong

Hopefully, this sheds light on why answer choice C is the right answer.