Explanation: CPA stands for **Closest Point of Approach**. In the context of ARPA (Automatic Radar Plotting Aid) systems used on ships, CPA is a critical calculation for collision avoidance. ARPA uses radar data to track other vessels and projects their future positions based on their current course and speed relative to your own vessel. The CPA is the minimum distance that another vessel will reach in relation to your own if both vessels maintain their current course and speed. This calculation, along with TCPA (Time to Closest Point of Approach), allows navigators to assess collision risk and determine if a course or speed alteration is necessary to ensure safe passage. Therefore: * **D) The closest point a ship or target will approach your own ship** is correct because it directly defines CPA as the minimum relative distance. * **A) The furthest point a ship or target will get to your own ship’s bow** is incorrect as CPA refers to the *closest* point, not the furthest, and it's a relative distance, not just to the bow. * **B) Direction of target relative to your own ship’s direction** describes a bearing or relative bearing, not the calculated closest distance. * **C) The combined detection and processing of targets** describes the general function of the ARPA system itself, rather than the specific calculation of CPA.