If he didn't have a good mark, his father wouldn't give him a gift.
A) He tried hard to get a high mark but his father couldn't persuade him
B) As he was a hardworking student, his parents always give him gifts
C) Unless he had a good mark, his father won't give him a present
D) Though he failed in the exam, his father congratulated him
E) Whenever he gets a good mark, his father is proud of him