下列属于货币市场利率工具的有（）。

A.各国政府发行的中长期国债

B.商业票据

C.可转让定期存单

D.短期国库券

We don't doubt _______ the boy can _______ the angry teacher. [ ]

A. if; apologize for

B. whether; apologize to

C. that; apologize to

D. what; apologize