What must a sentry do according to the Sixth General Order?

The Sixth General Order emphasizes the importance of a sentry's responsibility to ensure proper communication and adherence to orders within a security context. By stating that a sentry must "receive, obey, and pass on all orders from designated officers," this order underscores the criticality of maintaining the chain of command. It ensures that the sentry not only follows the orders given to them but also communicates effectively with other members of the security team. This helps maintain organization, discipline, and operational effectiveness in security operations, allowing for quick and efficient responses to incidents or emergencies.

The other options, while relevant to the duties of a sentry, do not encapsulate the core requirement put forth by the Sixth General Order. Reporting violations, speaking only when necessary, or sounding the alarm in emergencies are all important aspects of a sentry's role, but they do not express the fundamental duty of receiving, obeying, and relaying orders as structured by the General Orders governing sentry conduct. These directives collectively ensure that sentries act consistently in accordance with established protocols for effective security management.