The correct answer is B) Stations not directly involved with the on-going Distress communications may not transmit on the distress frequency or channel. "Radio silence" refers to a protocol where stations not directly involved in a distress situation are required to cease transmissions on the distress frequency or channel. This allows the stations handling the distress communication to coordinate the response without interference from other stations. The regulation ensures the distress frequency remains clear for the critical communications between the distressed vessel, rescue coordinators, and any vessels or aircraft involved in the rescue effort. The other options are incorrect because they do not accurately describe the meaning of "radio silence" in the context of maritime distress communications.