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

The Fifth General Order of a Sentry establishes the fundamental responsibility of a sentry to remain at their post until they have been properly relieved. This is crucial for maintaining security and order within a given area. By adhering to this order, a sentry ensures that their duties are fulfilled and that there is no lapse in vigilance that could compromise safety or security.

The notion of being "properly relieved" typically means that another designated individual has been assigned to take over the guard duty, ensuring continuous observation and protection of the area. This process is essential for the operational integrity of military functions and reinforces the accountability of those on duty. The authority granted to a superior does not apply unless it is accompanied by the action of proper relief, which is why the other options do not align with the correct interpretation of this military directive.