Which of the following be going to + infinitive construction is used to express intention?

A.He is going to be a teacher when he grows up.

B.I feel dizzy. I think I am going to faint.

C.George is putting on weight. He is going to be quiet fat.

D.Look at these black clouds — there is going to be a storm.

正确答案：He is going to be a teacher when he grows up.