Q4 - Kim: Some people claim

[WaltGrace1983]

This is a necessary assumption question:

It takes electricity to recharge electric car batteries
+
This would require building more generating facilities
→
Swapping out the gas-powered cars for electric ones would, at best, be swapping one source of fossil-fuel pollution for another

Without a solid understanding of a few key words, you will get thrown for a loop on this one. I think the most important distinction here is that the author is not saying that electric cars will foster any more or less pollution than gasoline cars. Instead, the author is saying that, even upon taking away one source of pollution in the gasoline cars, we are just getting another. Thus, to really understand this argument as effectively as possible, you need to realize the "swapping one source" part.

In addition, you got to think about possible assumptions before going on to the answer choices. What could the author be assuming here? Well what if the facilities and the electricity used to make cars/power batteries/etc. are all made by solar energy, not fossil fuels? The author is making a giant assumption that all of these things that keep electric cars running will be powered by fossil-fuels.

(A) We don't care about the total amount of cars on the road! Is this an exchange for one source of fossil-fuel pollution or not?

I am going to skip B and come back to it later

(C) "Justification" is the key word here. We don't need anything to be justified. The author is not saying that replacing the gasoline cars is an okay thing to do or that it is justified to do such and such action. This simply doesn't matter and the LSAT is trying to get you to make a leap that we are not warranted to make. That leap is going from fossil-fuel pollution to "justification."

(D) It is perfectly fine for the electric car to cause some significant air pollution. The key thing to think about here though is what kind of pollution. Is it fossil-fuel pollution? Well that is actually the question that this whole stimulus is based on.

(E) This one looks good. So the argument is telling us that "generating facilities" generate the power for electric cars. But what if that power is not coming from burning fossil-fuels? This negation of answer choice (E) would make the conclusion not follow from the premises and that is why this is correct.

Now let me return to (B) and discuss some important things to consider about it. If I was solving this in real-time, I would choose (E) but give one final thought to (B), the other answer choice that looked okay, before moving on to the next question. I actually thought that (B) looked decent upon review. I very quickly eliminated it when I was initially solving the question timed but during review I have time to think about every which way this argument could go.

My thought process for (B) was the following: "Well if gasoline-ppowered cars are the most significant source of fossil-fuel pollution then maybe no matter what happens the electric car will pollute less than the gas-powered car." However, this is a gross misrepresentation of the conclusion. The conclusion, as I have said, is not about which one pollutes more or less! It is about how the electric cars are just "an exchange of one source of fossil-fuel pollution for another." You can see how the LSAT is trying to trick you here but if you are ever in doubt, just reread the core and remember, "oh yea! That is what I am looking to help justify from the premises!"