患者女，50岁。拟行子宫内膜癌根治术。现稍活动即感心慌、气短。既往有27年风湿性心脏病史，曾发生心力衰竭3次。X线胸片、彩色多普勒超声诊断为二尖瓣狭窄并关闭不全，中度肺动脉高压。ECG检查示房颤。

患者的ASA分级是（）

A.Ⅰ级

B.Ⅱ级

C.Ⅲ级

D.Ⅳ级

E.Ⅴ级

An analyst does research about hypothesis testing and conducts a significance test to determine if the relationship between two variables is real or the result of chance. His null hypothesis is that the population correlation coefficient is equal to zero and his alternative hypothesis is that the population correlation coefficient is different from zero. He develops the following information:

A. one-tailed test and can reject his null hypothesis.

B. two-tailed test and can reject his null hypothesis.

C. two-tailed test and can not reject his null hypothesis.