Having prepared himself well for the realtor exams and having exhausted everyone in the family with his requests that someone help him with the true-and-false drills， Jeffrey， who had never been a particularly good student in high school， knew he was ready to take on the greatest challenge of his life.

A.This sentence is correct

B.drills； Jeffrey

C.Jeffrey - who had never been a particularly good student in high school - knew

正确答案：This sentence is correct