张某是专业摄影师，欲赴日本探亲，邻居陈某特别委托张某购买SONY摄像机一部。2个月后，张某回国，带回SONY摄像机一台，价值1万元，送至陈某家。但此时陈某已经去世，陈某的儿子以父亲已去世为由拒绝收下摄像机。请回答下列各题。

下列说法正确的是：()

A．张某的代理行为有效

B．陈某已经死亡，张某的代理行为无效

C．陈某的儿子无责任承受该代理行为的结果，支付摄像机价款

D．陈某的儿子有责任承受该代理行为的结果，支付摄像机价款

—Excuse me , could you please tell me which gate______?

—Er , sorry , I don’t know that ,either . [ ]

A. we have to go to  

B. we had to go to

C. did we have to go to  

D. should we have to go to