甲亢病人术后出现手足抽搐，最有效的处理措施是（）。

A.限肉类、乳品和蛋类等高磷饮食

B.服用双氢速变固醇油剂

C.静脉缓慢推注10%葡萄糖酸钙或氯化钙10～20ml

D.口服葡萄糖酸钙或乳酸钙

E.服用维生素D₃

His mother, with his aunt ____ now. 

A．are doing shopping

B．is doing shopping

C．do shopping

D．does shopping