When is your birthday?[ ]

A. My birthday is December seventeenth.

B. My birthday is seventeenth December.

C. My birthday is December seventeen.

维修返回的板件附带《返修设备收货反馈单》，该单由办事处板件管理员保留，并保留（）以备查验，返修流程结束。

A.3个月

B.6个月

C.12个月

D.24个月