某女，40岁，两年前出现多关节游走性疼痛，渐出现多个指间关节疼痛、肿胀、僵硬，晨起明显。查体：多个指间关节呈梭形肿大，左腕半固定，肘关节鹰嘴附近可触及无痛性结节。

为了明确诊断，应进一步检查（）

A.血常规

B.血沉

C.C反应蛋白

D.CT

E.类风湿因子

A company is planning a $50 million expansion. The expansion is to be financed by selling $20 million in new debt and $30 million in new common stock. The before-tax required return on debt is 9 percent and 14 percent for equity. If the company is in the 40 percent tax bracket, what is the marginal weighted average cost of capital（）

A. 10.6%.

B. 9.0%.

C. 10.0%.