1.-- Jenny has failed to seek advice from Professor Li on th

1.-- Jenny has failed to seek advice from Professor Li on the problem again.
-- What a shame!If only she ___ before he went abroad on business.
A.arrived B.had arrived C.should have arrived D.could have arrived
B的语法可以理解...不过D的问题在哪里呢?
2.-- Sorry,Jane.That wasn't of much help to you.
--Oh,___ .As a matter of fact ,it was most helpful.
A.sure it was B.it doesn't matter C.of course not D.never mind
为什么选A呢...实在不理解这逻辑= =