Though we don’t know what was discussed, yet we can feel the topic_____.

A．had changed

B．will change

C．was changed

D．has been changed

在一笔出口业务中，付款方式采用信用证和D/P即期各半，为收汇安全，应在合同中规定( )。

A．开两张汇票，各随附一套等价的货运单价

B．开两张汇票，信用证项下采用光票，托收项下采用跟单汇票

C．开两张汇票，信用证项下采用跟单汇票，托收项下采用光票

D．开一张汇票即可