This is the book ______we are looking for.

A．who

B．which

C．whose

D．Whom

血管扩张药改善心衰的心脏泵功能是由于（）

A.改善冠脉血流

B.减轻心脏前后负荷

C.降低外周阻力

D.降低血压

E.减少心输出量