Question

Supply a verb in agreement with its subject:
Each participant ___________ asked to complete a survey.

• A. put
• B. take
• C. was
• D. were

Answer 1

Answer: (C)

It is to be kept in mind that Either, Neither, Each, Everyone, Many a, must be followed by a singular verb.
'Each participant' means each individual participant. So, we are referring to a singular noun. By the general convention, a singular noun takes a singular verb. Hence, Option D 'was' is correct and Option C 'were' is incorrect.
Options A and B are irrelevant to the context.