加味二妙散主治之痿病主要见下列那些症状（）

A.四肢痿软、身体困重

B.发热、胸脘痞闷

C.食少纳呆、腹胀便溏、眩晕耳鸣

D.面浮不华、气短、神疲乏力、小便短赤

E.舌红体大苔黄腻，脉细数而濡

You are looking at two assets, A and B. The expected return on A is 15%, and the expected return on B is 17% , while the standard deviation of A is 20%, and the standard deviation of B is 18%. The two are correlated at 45%. What is the standard deviation of a portfolio made up of 40% A and the rest in B

A．

B．

C．