-- Perhaps Tom's not in.

-- ________. Look, the light's on.

A．Yes, he can be at home

B．No, he mustn't go out

C．Yes, he must be at home

D．No, he needn't go out

下述关于螺内酯作用特点的描述，正确的是（）

A.具有抑制心肌纤维化的功能

B.利尿作用强，药效持久

C.其利尿作用与体内醛固酮浓度无关

D.对肝硬化者无效

E.对肾小管的各段均有作用