46F3 B
 Which of the following frequencies have been designated for "On-scene" communications in the Global Maritime Distress and Safety System?
A. VHF Ch-22.
B. VHF Ch-16 and SITOR (NBDP) on 2174.5 kHz.
C. HF radiotelephone on 21.820 MHz.
D. SITOR (NBDP) on 2177.0 kHz and VHF Ch-16.
