Signals for locating will be transmitted in the 9GHz band by means of（）.

A.keep silence
B.interfere with such communication
C.establish communication as directed and render such assistance as is required and appropriate
D.refuse communication as directed and render such assistance as is required and appropriate

A.any appropriate channel except public communication
B.any appropriate channel except for public communications
C.any appropriate channel besides public communication
D.any appropriate channel beside public communication

A.between ship stations and shore-based communication networks
B.concern the management and operation of ships
C.may have an impact of the safety on ships
D.all of A, B, C