Bioluminescence, the biochemical emission of light by living organisms, is found in many marine species. Evolutionary biologists—many of whom ______ this trait to understand predation and mating signals—have traced its independent evolution nearly one hundred times.

9
reading

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

A

studies

B

has studied

C

study

D

is studying

Correct Answer: C

Choice C is the best answer. The relative pronoun "whom" refers to "evolutionary biologists" (plural). Therefore, the verb in the relative clause must be plural. "Study" is the plural present tense form.