问题

_______ one and a half months enough for the project to be finished?— I am afraid not. The professor is ill and only after he recovers ________ go on with it.[ ]
A: Is; he can
B: Are; he can
C: Is; can he
D: Are; can he
B: Are; he can
C: Is; can he
D: Are; can he
正确答案是: