Explanation: An autopilot's fundamental task is to maintain a vessel on a desired course. To achieve this, it requires two primary inputs: "course information" and "rudder feedback." **Course information** is the desired heading or track that the operator sets for the autopilot to follow. This is the target value the system aims to achieve. **Rudder feedback** informs the autopilot about the current position, angle, or effect of the rudder. This feedback is critical for the autopilot to know how its steering commands are being executed and how the vessel is responding. By comparing the actual heading (measured by a compass or gyro) against the desired course and knowing the rudder's action, the autopilot can make precise adjustments to keep the vessel on track, forming a closed-loop control system. The other options are incorrect because: * **A) Course information and GPS:** While GPS can provide course *guidance* (e.g., a track to a waypoint), the autopilot still needs specific heading information and rudder feedback for direct steering control. GPS is more of a navigational *input* that might *generate* the course information. * **B) Rudder feedback and Radar data:** Radar is for collision avoidance and navigation, not a direct input for the autopilot's steering function. * **D) Rudder feedback and yaw sensors:** Yaw sensors measure the vessel's rotational movement and are part of the internal feedback loop to determine the actual heading and deviation. However, "course information" (the desired target) is still the essential input the autopilot is trying to maintain, making "rudder feedback and yaw sensors" incomplete as the core *inputs*.