When will the float-free emergency position indicating radio beacon be activated after abandoning ship?（）

A.Immediately after floating free

B.After about one hour when the salt water activates the battery

C.Only when keyed by the radar of another vessel

D.Only when daylight activates the photovoltaic cell

I wish you success in your career.（）

A.You are welcome.  

B.I think so 

C.Yes, please.

D.The same to you.