In the following questions, in the given sentences, a part of the sentence is underlined. Beneath each sentence, four different ways of phrasing the underlined part are indicated. Choose the best alternative.

The manager was unhappy at Gaurav because he did not complete the work in time

A. is unhapy at

B. is to be unhappy at

C. was unhappy with

D. No correction required

Please do not use chat terms. Example: avoid using "grt" instead of "great".