Which jump-seats must be occupied by crewmembers during a flight?

During a flight, specific jump-seats must be occupied by crewmembers to ensure safe operations and to maintain proper crew resource management. The correct answer includes both the jump-seats situated in the first row (often designated for the flight deck crew) and those within the cabin that are equipped for use by cabin crew members.

This requirement is in place because the presence of trained crew members at designated jump-seats ensures that there is always an available staff member to respond to emergencies and assist passengers if needed. Additionally, having crew members in those specific jump-seats allows for efficient communication with the flight crew and enhances overall safety and coordination during the flight.

The other options would not fully address the requirement for crewmember presence in specific seating arrangements, as they either allow for randomness in jump-seat occupancy or limit the occupation to only the first row, which does not fulfill regulatory safety requirements. Having crew stationed effectively throughout the aircraft is essential for maintaining operational integrity and passenger safety.