A.A compulsory vessel must carry at least two licensed GMDSS Radio Operators
B.A compulsory vessel must satisfy certain equipment carriage requirements that are determined by where the vessel sails
C.A compulsory vessel must be able to transmit and respond to distress alerts
D.All of the above

A.It will abort the transmission and set off an audible alarm that must be manually reset
B.It will initiate the DSC distress alert but，as no information will be transmitted，rescue personnel will not be able to identify the vessel，its position or its situation
C.It will initiate the DSC distress alert and default information will automatically be transmitted
D.It will initiate the DSC distress alert，but any station receiving it will have to establish contact with the distressed vessel to determine its identity，position and situation