If your vessel is equipped with a radiotelephone，what must also be aboard?（）

A.The transmission is aborted and an alarm sounds to indicate this data must be provided by the operator
B.The transmission is not initiated and "ERROR" is indicated on the display readout
C.The transmission will be made with "default" information provided automatically
D.The receiving station will poll the DSC unit of the vessel in distress to download the necessary information

A.or
B.and
C.but
D.unless

A.identify
B.identifier
C.identity
D.identification