At what altitude or after what duration of time does the aircraft exit the takeoff CAS message inhibit period?

The correct choice stipulates that the aircraft exits the takeoff CAS message inhibit period at 400 feet Above Ground Level (AGL) or after 60 seconds have elapsed. This is significant because during takeoff, certain caution and advisory messages are inhibited to prevent them from distracting the flight crew as they perform critical phases of flight.

The specific altitude and time selected for this inhibition period are based on safety protocols that account for the most critical phases of takeoff and initial climb. At 400 feet AGL or after 60 seconds, the aircraft has usually established a safe climb, allowing the flight crew to receive all necessary updates without being overwhelmed by potentially irrelevant information during a critical phase of operations.

Setting these thresholds at 400 feet and 60 seconds improves flight safety and operational efficiency, enabling pilots to focus on maintaining control of the aircraft while allowing for the gradual reintroduction of caution and advisory messages that may require attention during regular operation.