Which cargo doors must be opened after a flight arrives?

The correct choice is that all cargo doors must be opened after a flight arrives to ensure the safety and efficiency of cargo operations. When a flight lands and the aircraft is parked, it is essential to access all compartments where cargo is stored. This is important for several reasons:

1. Cargo Handling: Opening all cargo doors allows ramp agents to evaluate the condition of the cargo, ensure that it has not shifted during transit, and prepare for unloading.

2. Safety: Ensuring that all compartments are accessible is important for safety inspections. This includes checking for any hazards or irregularities within each compartment that might affect the handling of the aircraft or the cargo itself.

3. Operational Efficiency: By opening all doors, ramp agents facilitate a smoother unloading process, as they can loop cargo transfer equipment through various access points, minimizing delays caused by limited access.

This approach aligns with standard operating procedures within the airline industry, ensuring that all necessary protocols for handling and inspecting cargo are followed thoroughly, preventing any oversights.