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

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

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

the statue probably looks very much like it would have looked if she had lived to complete it.

[BACKGROUND]. However, because [SUPPORT], [STILL SUPPORT], [CONCLUSION].

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

(A) …revised substantially throughout a series of dozens of preliminary sketches.

The implication here is that the “three sketches” might not have looked anything like what Barajas herself would have ended up creating. And that throws a big wrench in the author’s conclusion.

(B) One of the assistants…did not participate..

Cool. One of how many? We have no idea. Even if there are only two assistants this may not mean anything, but what if there are fifty? This doesn’t impact the conclusion.

(C) …materials that Barajas did not frequently use…

The passage doesn’t mention “materials”, and it’s not just common sense how that affects whether the statue looks “like it would have looked”. So this gets eliminated for sure.

(D) Barajas always worked from sketches…

Since the conclusion is only about “the statue”, it doesn’t matter what she “always” did. This doesn’t tell us anything we didn’t already know about this one specific case.

(E) Barajas never took as long…

This definitely doesn’t matter since the conclusion is only about what it looks like when it’s “complete”.

(A) is the correct answer.