Which of the following statements about transmitting distress messages by radiotelephone is INCORRECT?（）

A.If no answer is received on the designated distress frequencies，repeat the distress call on any frequency available
B.Channel 16 (156.8) may be used for distress messages
C.It is advisable to follow a distress message on 2182 kHz by two dashes of 10 to 15 seconds duration
D.Distress messages should first be transmitted on 2182 kHz

A.A continuous sounding with any fog signal apparatus
B.A signal sent by radiotelephone consisting of the spoken word "Mayday"
C.An International Code Signal of N.C.
D.The firing of green star rockets or shells

A.A triangular flag above or below a ball
B.The International Code Signal of distress indicated by "JV"
C.A green smoke signal
D.Flames on the vessel as from a burning tar barrel