PT62.S4.Q18 - If there are sentient beings on planets outside

glaezzo

Hello,
Here is my reasoning for question 18 in section 4 for prep test 62. Since this is a sufficient assumption question, I want to be able to find a “connector” that would assure the conclusion from the premises, or evidence given.
Argument Analysis:
Premises:
• We can’t reach E.T aliens via spaceship
• If we can talk with the E.T aliens, then they need to be as smart as we are (most likely so they can understand what we are saying to them).
Conclusion:
• If there are E.T aliens, we won’t be able to know this unless they are as smart as we are.
Prephrase:
Initially, I was trying to look for something along the lines of connecting being able to communicate with the E.T aliens that are as smart as we are. For instance, maybe we don’t have the technology to transmit messages to them or perhaps they want their identity to remain hidden for all of eternity. However, looking more closely to the set up of this argument I found another primary issue. The issue is that we are only given two options for determining if they exist. Well, couldn’t there be other ways? For example, (this is purely made up) maybe we could get into a teleportation machine and teleport ourselves to their planet or we could build a massive slingshot to sling ourselves to their planet. My gist is that we have to get to the idea that it is necessary that the aliens be as smart as we are in order to determine if any actually do exist in the entire galaxy.
Answer Choices:
A. No. This doesn’t work because the person never rules this out.
B. I don’t believe that this guarantees anything. Maybe we could send them a signal and if they accept it, then we know there is life. A conversation isn’t necessary to prove that there is life.
C. No not need, the author never suggests that we need both options to determine if they exist.
D. Yes, because this AC rules out all other choices and substantiates the necessary condition in the conclusion.
E. This is slightly a premise booster and slightly a reversal of one of the premises mentioned in the stimulus.

Problem: My major problem with this question is that answer choice B is very compelling for me and I am afraid that I would select it during a timed test.
It would be great if I could have further feedback on why B is wrong or what we need to do for this particular type of SA question.

Admin note: edited title and added link: https://7sage.com/lsat_explanations/lsat-62-section-4-question-18/

BlindReviewer

Your analysis is really good, and under timed conditions I just pre-phrased like you did and went looking for the answer that most matched. The others I quickly eliminated without considering them too much because they didn't seem to get at the crucial point you bring up -- that we're concerned with our ABILITY to determine the existence of other sentient beings outside our solar system, not a certainty that we will.

I find B to be similar to E in that both of them 1) seem to be "necessary" assumptions and 2) don't have anything to do with the main flaw/gap we need to fill for the argument to work. For B, it might seem necessary that sentient beings outside our solar system must want to communicate with us to ensure that the "exception" to the conclusion (that we can't determine their existence unless they're smart enough to contact us) holds true, but is it really? We don't need every alien to want to contact us, we just need SOME aliens to want to contact us.

More importantly, one way to check SA answer choices is to plug them in and see if they actually guarantee the argument. Let's say all smart aliens want to communicate with us. So what? That doesn't rule out the possibility of, like you say, a teleportation machine, or, as I thought, some kind of radio signal or satellite (I admit your idea is cooler). E is similar but just replaces "want" with "capable."