Which of the following is a key responsibility of the pilot in command?

The key responsibility of the pilot in command is to ensure the safety of the aircraft. This role encompasses a broad range of duties that include not only making decisions regarding the operation of the aircraft but also managing the safety of all personnel on board, as well as the aircraft itself. The pilot in command is accountable for every aspect of the flight, which involves assessing conditions, making critical decisions during emergencies, and adhering to regulatory requirements and safety protocols. This overarching responsibility is fundamental to aviation operations and is the primary focus of the pilot's duties.

While filing a flight plan, communicating with air traffic control, and managing fuel levels are all important tasks that contribute to the successful completion of a flight, they fall under the larger umbrella of ensuring safety. If any of these responsibilities are neglected or mishandled, it could jeopardize the safety of the flight, highlighting why the safety of the aircraft remains the pilot in command's top priority.