I am sure he did not know that his brother graduat...

Câu hỏi: I am sure he did not know that his brother graduated with flying colors. 

A He should not have been envious of his brother’s achievement.

B  He cannot have known that his brother graduated with very high marks.

C That his brother graduated with flying colors must have been appreciated by him.

D  He may not know that his brother is flying gradually up in a colorful balloon.