The following question, consist of two words each that have a certain relationship to each other, followed by four lettered pairs of words. Select the lettered pair that has the same relationship as the original pair of words:
Signal : Traffic

A. Dam : River

B. Lens : Light

C. Door : House

D. Operation : Doctor

Answer: Option A

Solution(By Examveda Team)

First controls the flow or movement of the second.