As the header states, I didn't see any blatantly wrong with the argument. It was just a causal chain (Global warming causes temperatures to increase which causes greater proportion of precipitation to fall as rain which causes faster melting and more flooding and less storable water) and I didn't notice any significant gaps and so all the answer choices just looked and sounded correct. What do I do in a situation like this? I also thought JY's explanation for answer choice A was a stretch. I think it's correct to assume precipitation in this instance is referring to rain.
Admin note: https://classic.7sage.com/lsat_explanations/lsat-71-section-1-question-12/