Explanation: GMDSS equipment, crucial for maritime safety, must undergo mandatory inspections more frequently than every five years. Under international regulations (SOLAS Chapter IV), GMDSS radio installations are required to be inspected at least once every **12 months** by an authorized surveyor to ensure operational readiness and compliance. This annual inspection is vital for maintaining the integrity of distress and safety communications. * **A) is true:** Administrations (flag states) can indeed grant conditional or partial exemptions in exceptional circumstances, usually for a single voyage, as permitted by SOLAS Regulation I/4. * **B) is true:** The GMDSS regulations apply broadly to all passenger ships regardless of size and to cargo ships of 300 gross tons and upwards engaged on international voyages (SOLAS Chapter IV, Regulation 2). * **C) is true:** To ensure continuous watchkeeping and operational capability, most GMDSS-equipped ships, especially those sailing offshore, are required to carry at least two persons qualified to perform distress and safety radiocommunication functions, each holding a GMDSS Radio Operator's license (SOLAS Regulation IV/16.1).