Final answer:
Cabin crew should wear seatbelts during takeoff, landing, and when the seatbelt sign is activated such as Option b) "During the entire flight".
Step-by-step explanation:
Cabin crew members should be wearing seatbelts during the entire flight, as safety regulations and standard operating procedures mandate their use for the duration of the journey. Option b) "During the entire flight" is the correct choice. This practice ensures that cabin crew are secured in their seats in case of unexpected turbulence or other unforeseen events that could pose a safety risk. While turbulence is a common trigger for seatbelt use, it's essential for cabin crew to be prepared for any situation that might necessitate restraint, including sudden changes in altitude or other emergencies. This precaution is in line with aviation safety protocols, emphasizing the importance of cabin crew readiness and safety compliance throughout the entire flight, not just during specific phases like takeoff and landing. Wearing seatbelts during the entire flight contributes to the overall safety and well-being of both passengers and crew.