Explanation: SafetyNET is a global, satellite-based service under the Global Maritime Distress and Safety System (GMDSS) for broadcasting Maritime Safety Information (MSI) to ships. It specifically utilizes the Inmarsat-C satellite system. Ships receive SafetyNET messages via the Enhanced Group Call (EGC) receiver, which is an integral component of the vessel's Inmarsat-C Satellite Earth Station (SES). This ensures reliable reception of navigation warnings, weather forecasts, and search and rescue information worldwide. VHF DSC (B) is for short-range digital selective calling, not a SafetyNET broadcast receiver. NAVTEX (C) is a terrestrial medium-frequency (MF) telex system for MSI, operating on 518 kHz, and is distinct from the satellite-based SafetyNET system. HF SITOR (NBDP) (D) is also a terrestrial high-frequency (HF) system for MSI, not the satellite-based SafetyNET.