In the following questions, a sentence has been divided into four parts and marked a, b, c and d. One of these parts contains a mistake in grammar Idiom or syntax. Identify that part and mark it as the answer.

A. The student, who the friends have nicknamed

B. Jolly John, bunks classes often

C. and goes to movies even after

D. repeated warnings by the teacher

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