What action should you take after sending a false Distress alert on 12577.0 kHz?

Correct Answer: Option C — Make an "ALL SHIPS" call on the associated 12 MHz J3E frequency canceling the alert.

When a false DSC alert is transmitted on HF, the operator must cancel it by broadcasting a voice announcement on the corresponding J3E radiotelephone frequency for that band. This ensures that all monitoring stations are informed of the error, preventing unnecessary search and rescue mobilization efforts.