The hospital ________ well, where many wounded _________ every day. [      ]

A. is operated, operation

B. operates, are operated on

C. operates; are operated

D. operates; operates on

男性，48岁，近1周内发现血压升高156/98mmHg，服用利尿剂氢氯噻嗪降压效果不佳，且出现四肢行走无力，测血钾为2.2mmol/L。

若需明确诊断，则下一步需作

A．测定血17-羟孕酮

B．停用利尿剂4周后测定尿钾排泄率

C．立即测定肾素、血管紧张素

D．立即行立卧位醛固酮试验