Explanation: Under GMDSS (Global Maritime Distress and Safety System) regulations, particularly those outlined in SOLAS (Safety of Life at Sea) Chapter IV, essential safety equipment must be readily available and fully functional. A compulsory VHF-DSC (Digital Selective Calling) radiotelephone is a primary means of distress alerting and communication. **B) Daily:** GMDSS requirements mandate daily operational checks of critical equipment like the VHF-DSC to ensure its immediate readiness for distress situations. This typically involves performing a self-test or a test call function to verify basic functionality. **A) Annually, by a representative of the FCC:** While GMDSS installations undergo annual surveys by authorized personnel, this is a comprehensive inspection and does not replace the need for daily operational checks by the ship's crew. The FCC primarily regulates US vessels and licensing. **C) At the annual SOLAS inspection:** Similar to option A, the annual SOLAS inspection is a formal survey. Daily checks are ongoing responsibilities to ensure constant operational status. **D) Monthly:** Monthly checks are insufficient for equipment critical for immediate distress alerting. The urgency of maritime safety demands more frequent verification.