until until和unless时态上用法有没有一样

until until和unless时态上用法有没有一样
Don't discuss the problems with your partner until you______to do so.
A.ask B.are asked C.will ask D.will be asked
这道题书中给出的答案是选D,总觉得不对,到底要选哪一个,请大侠们指点
还有这道题和下面这道题有什么不同
Don't discuss the problems with your partner unless you___B___to do so.
A.ask B.are asked C.will ask D.will be asked