How will the right answer fit in terms of support and conclusion?

Only the right answer will add support for disagreeing with the conclusion, or for the opposite conclusion.

Highlight the main conclusion in the passage, if there is one:

our most important intellectual skills will similarly be devalued by electronic data-processing technology.

[SUPPORT]. Clearly, [CONCLUSION]. [SUPPORT].

Good on you for seeing that this argument is making a comparison. But you also caught that the conclusion totally changed the subject, right? Where did “most important intellectual skills” come from? The support only mentions “computations”. So, the right answer could say the comparison is faulty for some reason. But it’s more likely the author will get called out for that big shift in the wording.

Map the wording of the answers to the wording of the passage:

(A) Much industrial machinery is now designed…

This doesn’t matter at all. We’re talking about machines and computers replacing human workers, but this is about how computers are used to make machines. That’s a whole other subject.

(B) Before electronic data-processing technology…

This wants to be an easy out. The conclusion is about an effect of this technology, so what happened before it existed probably wouldn’t impact the argument much no matter what else this says.

(C) skilled mathematicians tend to be much younger…

Isn’t that fascinating? But this is pretty far out there. It doesn’t really map to the passage at all since there was nothing in there about age You’d have to add in quite a bit of your own reasoning to make this work.

(D) The intellectual skills that society values most are not computational ones.

Boom! This is the only answer that maps to the new wording in the conclusion, which is proof enough. But of course it also says the “skills” in the conclusion aren’t the “computations” in the support.

(E) …that previously could not be performed at all.

There’s nothing in the passage about enabling new tasks to be performed, just speeding them up.

(D) is the correct answer.

Common pattern/s in this question: Pattern fight! When you see two of the really common ones on the same passage, the right answer could go technically go either way. But usually the LSAT thinks new wording in a conclusion is the most egregious flaw. So expect right answers to call out that the author changed the subject for sure.