What is the primary function of the aircraft's autopilot system in the ERJ-145?

The primary function of the aircraft's autopilot system in the ERJ-145 is to control navigation and flight path. The autopilot system assists pilots by managing the aircraft’s flight trajectory, thereby allowing for more precise control during various phases of flight, such as climbs, descents, and level flight. This support minimizes the workload on pilots, enabling them to focus on other critical tasks such as monitoring systems and handling communication.

In the context of the other options, monitoring fuel consumption is typically handled by separate systems and gauges rather than the autopilot. Adjusting cabin pressure is an automatic function managed by the environmental control system, independent of autopilot control. Operating the engines is under the direct control of the pilots and involves specific manual inputs rather than being automated by the autopilot system. Therefore, the correct answer highlights the essential role of the autopilot in navigation and maintaining the designated flight path, which is crucial for efficient and safe flying.