Dr. Martinez is one of the researchers who _______ pioneering work in this field.

10
reading

Which choice completes the text so that it conforms to the conventions of Standard English?

A

has done

B

does

C

was doing

D

have done

Correct Answer: D

Choice D is the best answer. This question tests subject-verb agreement in relative clauses.

  1. Context clues: "Who" refers to "researchers" (plural).
  2. Meaning: The verb in the relative clause agrees with the antecedent of "who."
  3. Verify: "researchers who have done" correctly uses plural verb.

💡 Strategy: In "one of the [plural] who" constructions, "who" refers to the plural noun.

Choice A is incorrect because "has done" is singular. Choice B is incorrect because "does" is singular and wrong tense. Choice C is incorrect because "was doing" is singular.