“Mike is often absent from class.” “Tell him he _ _ answer for it if he goes on behaving like that.”

“Mike is often absent from class.” “Tell him he _ _ answer for it if he goes on behaving like that.” A. shall B. will C. would D. can

The correct answer is B. will.

The sentence would be:
"Tell him he will answer for it if he goes on behaving like that."

Here, "will" expresses a future consequence or result, which fits the context of the warning about Mike's behavior.