Under the International Code of Signals how are geographical locations such as New York City transmitted（）.

A.A commonly used abbreviation such as NYC is used

B.The name is spelled out

C.The geographical coordinates are used

D.The radio station call sign for the nearest marine radio station is used

服役期间的士兵亲属来队留住时间不超过（）天.

A、7

B、15

C、20

D、30