I believe the answer is C.) When the teacher attempted to discipline him, he was obstinate.
Obstinate means; “Stubbornly refusing to change ones opinions or chosen course of action, despite attempts to persuade one to do so.” The sentence states that the teacher is trying to discipline the boy, but he refuses to.
I hope this helps :))
The title of a book, film, or play, and if on paper, you underline it
