Which of the following is a primary responsibility of the captain on an aircraft?

The primary responsibility of the captain on an aircraft is the overall command and operation of the aircraft. The captain holds ultimate authority regarding all aspects of flight, including navigation, crew management, passenger safety, and adherence to regulations. This responsibility encompasses making critical decisions during various phases of flight, such as takeoff, cruise, and landing, especially in emergency situations. A captain must also ensure that all safety protocols are followed and that the aircraft is operated within its performance limits, ultimately prioritizing the safety and well-being of everyone on board.

While managing cabin safety, conducting in-flight service, and assisting passengers with boarding are important tasks typically performed by other crew members, the captain's role is centered on the aircraft's operational command. This distinguishes the captain’s responsibilities from those of flight attendants and other crew members, who focus more on passenger comfort and safety in the cabin environment.