Bunuel
Dadaism, the avant-garde European artistic movement of the early twentieth century, a phenomenon in which the postwar economic and moral sentiments gave birth to art that appeared to reject logic and embrace chaos.
A. a phenomenon in which the postwar economic and moral sentiments gave birth to art that appeared to reject
B. a phenomenon when the postwar economic and moral sentiments were giving birth to art that appeared, rejecting
C. a phenomenon in which the postwar economic and moral sentiments appeared and give birth to art that rejected
D. was a phenomenon in which the postwar economic and moral sentiments gave birth to art that appeared to reject
E. was a phenomenon when the postwar economic and moral sentiments were giving birth to art appearing to reject
Official Explanation
Creating a filter: the original sentence is not, in fact, a sentence. There is no verb corresponding to the grammatical subject "Dadaism." Everything from "a phenomenon" on is a modifying phrase. So (A) is out.
Applying the filter: (B) and (C) are out on the same grounds as (A), as we can see by looking at their first few words. In answer choice (E), the use of "when" is incorrect, because a "phenomenon" is not a time.
The correct answer is (D).