What does the second general order state?

The second general order states that a sentry must "walk my post in a military manner, keeping always on the alert." This emphasizes the importance of maintaining an active and vigilant presence while on duty. By using the term "military manner," it highlights that sentries are expected to uphold a professional demeanor that reflects discipline and obedience to military standards.

Remaining alert is crucial within a military context as it ensures readiness to respond to any situation that may arise. The element of vigilance not only aids in the effective performance of duties but also contributes to the overall safety and security of the area being protected. This order serves as a foundation for operational readiness and situational awareness, which are key responsibilities for any military personnel on duty.

Other choices, while they pertain to military orders and protocols, do not encapsulate the essence of the second general order regarding the conduct of sentries. Each of those orders relates to responsibilities in different contexts, such as communication and compliance with superiors, but it is the requirement to maintain an alert presence while on post that characterizes the second general order specifically.