Thanks for the question! Let’s take a look at the stimulus. We’re told that older US automobiles contribute a disproportionate amount to global air pollution. Many automobiles have been taken out of service by emission-control inspections as owners buy newer automobiles. The argument then concludes that those older US automobiles contribute to the global atmosphere will be gradually reduced over the next decade.
Now we’re asked for something that would most seriously weaken the argument. Let’s take a look at (A), which tells us that it’s impossible to separate the air of one country or jurisdiction from another, since air currents circle the globe. This is likely true, but it doesn’t really answer the question, a trap that will occasionally be on the LSAT. Yes, it’s hard to tell what air belongs to who. But the question is about whether or not the cars will contribute less to global air pollution because of emissions, and that doesn’t depend on which country or jurisdiction the air goes. And the exhaust that comes out of cars can be measured and attributed to a certain country much more easily. (A) doesn’t really weaken the argument, and so it’s not correct.
Hope this helps! Feel free to ask any other questions that you might have.
