Explanation: Modern DSC (Digital Selective Calling) radios are specifically designed with a dedicated "Distress Hot Key" for immediate and rapid activation in an emergency. This key, often red, covered, or requiring a prolonged press, automates the transmission of a pre-formatted DSC distress alert. It includes your vessel's MMSI, current position, and time (if connected to a GPS), and sometimes the nature of distress. This design prioritizes speed and simplicity under duress, eliminating the need to navigate menus. Navigating menus to select "Distress" (A) or "Distress Relay" (D) would take longer than using the dedicated hotkey. Transmitting a "MAYDAY" call on Ch-16 (B) is a voice distress procedure, not a DSC digital alert, and while a critical part of distress communications, it is not the *quickest way to transmit a DSC Distress alert*. The hotkey ensures the fastest possible digital alert transmission as mandated by GMDSS (Global Maritime Distress and Safety System) regulations for maritime safety.