GRE verb Indefinite multiple choice

Question

Oil did not_______ the Mexican export boom beginning around 1910, but it certainly played a critical role in keeping the export sector buoyant during the early 1920s

A. creat

B. hasten

C. quash

D. cause

E. sustain

F prolong

Indefinite multiple choice

Answer 1

The answer should be cause, while some arguments can be made for create the economic boom is usually a causation not a creation. The other clues do not fit the narrative, the sentence is about starting of economic boom.

Answer 2

D, it is implied that the verb is a positive word and that it deals with the creation of the Mexican export