Explanation: Channel 16 is the international voice Distress, Safety, and Calling frequency for VHF maritime radio. All vessels and coast stations monitoring for distress communications are required to maintain a listening watch on this channel. When a false Distress alert is sent, it's crucial to immediately cancel it on Channel 16 via a voice announcement. This action ensures that all listening stations, including the Coast Guard and other vessels, are promptly informed that the emergency is not real. Failing to cancel a false alert can lead to unnecessary search and rescue operations, diverting critical resources. * **A) Send a DSC cancellation message on Ch-70:** This would be appropriate if the initial false alert was a DSC (Digital Selective Calling) distress alert sent on Channel 70. However, a voice alert requires a voice cancellation on Channel 16 to reach all listeners. * **B) Make a voice announcement to cancel the alert on Ch-13:** Channel 13 is primarily used for Bridge-to-Bridge navigational safety communications and is not universally monitored for distress or general calling. * **C) Make a voice announcement to cancel the alert on Ch-22A:** Channel 22A is a U.S. Coast Guard working channel, used for follow-up communications after initial contact on Channel 16, not for universal distress cancellation.