When placing a SSB MF/HF call to a Coast Station, you should always:

Correct Answer: Option B — Make sure the frequency is not occupied.

Before initiating any transmission on MF/HF, the operator must monitor the selected frequency to ensure it is not currently in use. This prevents interference with ongoing distress, urgency, or routine traffic, adhering to the fundamental principles of radio discipline and ITU-R M.541-10 regarding spectrum management.