I would have finished my paper if it was at all possible, but I was fully occupied the whole of last week.

A．had it been

B．were it

C．it had been

D．it were

信用证开立的基础是买卖合同，又是开证行对受益人的有条件的付款承诺，所以，当信用证条款与买卖合同规定不一致时，受益人可以( )。

A．要求开证行修改

B．要求开证申请人修改

C．要求通知行修改

D．自行修改