It was clear that he was ______ the people he owed money to. [ ]

A. at the expense of

B. at the risk of

C. at the mercy of

D. in the way of

按照股票的投资对象及定价币种的不同进行分类，我国股票可分为( )。

A．A股和B股
B．普通股与优先股
C．记名股与不记名股
D．国家股、法人股与社会公众股