According to FAR 121.481, what are the crew rest requirements?

The crew rest requirements under FAR 121.481 specify that flight crew members must have a minimum of 8 hours of rest between duty periods. This regulation is designed to ensure that pilots and other crew members have enough time to rest and recover, reducing fatigue and maintaining safety during flight operations. Adequate rest is crucial for optimal performance, decision-making, and overall safety in aviation. The requirement for a full 8 hours is a standard that aims to help ensure that crew members are adequately refreshed and alert for their next duty period.

The other options reflect different limits unrelated to the minimum rest requirements established by FAR 121.481. While they may pertain to time management or frequency of duties, they do not align with the specific stipulations for mandatory crew rest as specified in the regulation.