If _________, he promised that he would try his best to improve people's living conditions. [ ]

A. being elected

B. to be elected

C. having elected

D. elected

男，68岁，感冒发热给安痛定肌肉注射，第4天双下肢出现紫斑、尿少，查尿蛋白++（2．5g／d），尿RBC20～30个／HP，尿嗜酸性白细胞增高，提示：入院后查：血红蛋白110g／L，血清白蛋白31g／L，Scr740μmol／L，B超示双肾大。

提示：患者尿量较少，400ml／24h，第二天查Scr870μmol／L。提问：确定诊断的检查方法是()

A.双肾B超检查

B.肾小管功能检查

C.肾小球滤过率

D.血清肌酐

E.肾活检

F.双肾CT