Read the sentence given below to find out if it contains any error. The error, if any, will be in one part of the sentence. If the sentence is error free, select No error or option 5. Ignore error of punctuation if any.

As water temperature rises, the proliferate (A)/ of predators such as killer (B)/ whales could have influenced (C)/ the bowheads to stay put over winter. (D)/ No error (E)