Read the sentence given below to find out if it contains any error. The error, if any, will be only in one part of the sentence. If the sentence is error-free, select No Error or Option 5(E). Ignore errors of punctuation, if any.

The thief was awaiting (A)/ the impeccable opportunity (B)/ and when the security guard was soundly sleeping last night, (C)/ the devil made his move. (D)/ No error (E)