It looks like you're new here. If you want to get involved, click one of these buttons!
I was stuck between C and E for this question and chose the latter because the stimulus seemed to be more focused on extraterrestrial life. E can also be an actual reason for why we wouldn't know about life outside of Earth. How would you know to choose C over E? Why is it not the answer?
Comments
In the stimulus, Clay Moltz's argument begins at the word "Yet." Everything up until that word is just the context and not part of his argument. This is a weaken question and we are trying to weaken Clay's argument. So it is helpful to isolate his argument from the context, as to not get confused. His conclusion is that the astronomer is wrong and life only exists on Earth. Why does he think this? His premises are that astronomers have not detected even one planet outside of our solar system. Based on this premise, Clay makes the assumption that the lack of any evidence of other planets is equivalent to evidence that there are no other planets. This is a common flaw that appears on the LSAT and can be thought of "lack of proof is not proof of lack." If Clay had said "there is no evidence of other planets, so we can't know for sure whether there are other planets or not," then that would not be flawed. Yet, Clay goes the extra mile and says that because we don't have any proof, then other planets for sure don't exist. Now, (C) is the correct answer because it exploits this assumption and says "the detection of other planets requires technology that we don't have." This weakens Clay's argument because it opens up the possibility that the reason we haven't detected other planets is not because they don't exist at all, but rather that we just don't have the technology to do so yet. AC (C) creates doubt that Clay's conclusion is true because it provides a different reason for the absence of other planets, and thus weakens his argument. (E) says that any extraterrestrial civilization would have difficulty communicating with us. Clay's argument has nothing to do with extraterrestrial life, it only has to do with the absence of our evidence of other planets. Extraterrestrial life is mentioned in the context, but is not relevant to the assumption between the premises and the conclusion that we are trying to weaken. (E) may seem attractive because one might think it provides a reason as to why we don't have evidence of extraterrestrial life: because it is difficult. But even if it is difficult, it doesn't mean it's impossible. If they actually existed, they could still communicate with us, despite any challenges they would face. If it were true that it would be difficult for them to communicate, it would not weaken Clay's argument because he could say that the reason that we haven't had any communication with them is not because it is difficult, but rather because they don't exist. But more simply put, (E) is not the correct answer because it does not attack the assumption between Clay's premises and conclusion, and (C) does. Hope this helps a bit!