During which phases of flight must safety belts be fastened according to regulations?

The regulation regarding the use of safety belts mandates that they must be fastened from the moment the aircraft takes off until it has completely landed and come to a stop. This is to ensure that all occupants are secured throughout the phases of flight where turbulence or sudden maneuvers might occur, which could pose a risk of injury. Keeping safety belts fastened during this entire time helps to protect both passengers and crew in case of unexpected situations.

While some options suggest fastening belts only during specific phases, such as landing or taxiing, they do not consider the full range of potential hazards that can occur during the entire duration of flight. Thus, the requirement encompasses all stages from takeoff through to the cessation of movement after landing, making it critical to ensure safety throughout.