According to the fifth General Order of a Sentry, when can a sentry leave their post?

The fifth General Order of a Sentry states that a sentry must remain at their post until they are properly relieved. This emphasizes the importance of maintaining security and accountability while on duty. A properly relieved sentry ensures that another individual has taken over their responsibilities, preventing any lapse in vigilance or oversight that could lead to breaches in security.

While other options mention various scenarios in which a sentry might consider leaving their post, they do not align with the strict protocols governing sentry duty. The concept of being "properly relieved" reinforces military discipline and establishes a clear chain of responsibility, integral to maintaining order and safety within the unit.