Explanation: A Maritime Mobile Service Identity (MMSI) is a unique 9-digit number assigned to stations in the maritime mobile service. For a ship station, the MMSI always begins with a three-digit Maritime Identification Digit (MID), which ranges from 201 to 799. * **D) 623944326** is a 9-digit number starting with '623'. Since '623' falls within the 201-799 range, this indicates a ship station. Let's look at why the others are incorrect: * **A) 003372694** starts with '00'. This prefix designates a coast station. * **B) 030356328** starts with '0'. A single '0' followed by an MID typically indicates a group call station (e.g., for a fleet) or other specialized stations like an aid to navigation (AtoN) or aircraft. It is not a standard ship station MMSI. * **C) 3384672** is only 7 digits long. An MMSI must be 9 digits.