Explanation: Coast stations frequently have messages for ships that are not actively communicating with them. To notify ships of pending traffic, coast stations traditionally transmit lists of call signs (often referred to as traffic lists) at regular intervals on designated calling frequencies. Ships monitor these broadcasts, and if they hear their call sign, they then call the coast station to receive the message. This method ensures that ships, even those without continuous communication, are made aware of inbound messages. Option A is incorrect because while 2182 kHz and 156.800 MHz are calling frequencies, making a directed transmission without prior knowledge of the ship's readiness to receive is not the primary notification method for routine traffic. Ships primarily monitor for general calls or traffic lists. Option B is incorrect as ships do not typically maintain a dedicated "working frequency" constantly monitored for unsolicited calls. Option C describes Digital Selective Calling (DSC), which uses a ship's Maritime Mobile Service Identity (MMSI) to notify, but traffic lists (Option D) represent a broader, long-standing, and still valid method, especially for non-DSC equipped vessels or as a general broadcast procedure.