_____ he was very tired, he continued working in his office.

A．Since

B．Although

C．As soon as

D．Because

某机关单位召开一次会议预期12天，后因会期缩短4天，因此原预算款节约了一部分，其中生活费一项节约了4000元，比原计划少用40%，生活费预算占总预算的4/9，则总预算为（）。

A．45000

B．35000

C．27500

D．22500