下列关于中央银行的再贴现率说法正确的是（）。

A.再贴现率下降表示货币当局扩大货币和信贷供给

B.再贴现率下降表示货币当局减少货币和信贷供给

C.再贴现率上升表示货币当局扩大货币和信贷供给

D.表示政府采取旨在使收入分配公平的政策

In the US, students can do almost anything they want in class, ____ they don’t make too much noise or disturb others who want to learn from the teacher.

A．even though

B．now that

C．so that

D．as long as