_____ in the queue for half an hour, Tom suddenly realized that he had left his wallet at home. [ ]

A. To wait

B. Have waited

C. Having waited

D. To have waited

女性，35岁，人工流产后出现双手指关节疼3个月，伴晨僵约1小时左右，对症用中药治疗效果不佳；查体双手第1、2掌指关节（MCP）、2～4近端指间关节（17IP）肿胀，压痛明显，X线示关节间隙正常，双手骨质疏松，可见小囊性破坏样改变。

下列哪项指标最有利于判断病情的活动性（）

A.抗核抗体

B.ASO

C.C3、C4

D.类风湿因子

E.WBC