—Could you tell me ------- the final exam

—Could you tell me _______ the final exam —In about 30 days.A.when we will have B.when will we have.C.how soon we will D.how soon will we从A、B、C、D中选一个答案,B和D肯定是果断排除,关键是A和C,这种对“in+时间”的提问一般都是用“how soon”,但是C答案中没有动词“have”,之前本以为会不会是C答案中漏了一个“have”,所以想问问各位学长学姐,这种情况,可不可以用“when”提问 感激万分!