Explanation

By characterizing the distinction as “supposed” and “fabricated,” the sentence indicates that the distinction has no basis in reality. Accordingly, when the sentence reports a happy outcome, this must mean that the distinction has been abandoned or rejected. Only “eliminated” and “put to rest” convey that sense; all the other answer choices suggest that the distinction is maintained, or even strengthened.

Thus, the correct answer is eliminated (Choice A) and put to rest (Choice C).
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this was easy still i wasn't able to get it

Answers :A,C

to have been described whom?

Tell me Sir.

what did you not understand ?
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the phrase " have been " is referring to whom ?

The Keywords here are "supposed distinction" --> not real.

So, logically if artists have control then this distinction would not be there.
AC fits, and it is the answer.

Would be thankful if someone can break this down in layman terms.
I came back to this question after weeks and still selected the same options that I had earlier, showing that I am still failing to interpret the statement at its foundation

So, here's the question
In American Indian art, the supposed distinction between modern and traditional was fabricated by critics, and when artists have control over interpretation of their own work, the distinction appears, happily, to have been ________.

A eliminated
B reinforced
C put to rest
D intensified
E recognized
F established

In AI art(can be any art) as per critics there are distinctions(varying features) between traditional and modern forms. However, when artists interpret the distinctions are gone.

So, sentence elaborates the difference in the two interpretations and that difference is about possible distinctions of one over the other - modern and traditional.
Know that 'supposed' expresses assumption. Hence, as the structure of the sentence suggests, artists' interpretation should be opposite which only A and C elaborates.
B, E and F goes in same direction as critics'. D gives another meaning to the sentence, as in artists amplifying what critics say. Also, D can't be the answer as no other words matches to its meaning.

Answer A and C.