AFCAT II 26 AUG 2022 Shift 1 Paper

In the following question, the given sentence has four parts marked as A, B, C, and D. Choose the part of the sentence with an error and mark it as your answer. If there is no error, mark D as your answer.
My senior asked me (A) / whether I was interested (B) / to joining the group for the skit. (C) / No Error (D)