Which of the following is an example of a fixed post for a security guard?

A fixed post for a security guard refers to a position where the guard remains at a specific location or desk, rather than patrolling or moving around. Working at a front desk entails monitoring activities, checking identification, and assisting people as they enter a building, making it a clear example of a fixed post. This role often requires vigilance and customer service skills, as the guard is responsible for maintaining security at a designated entry point or location.

On the other hand, options that involve mobility, such as on foot patrol or patrolling in a mobile unit, do not exemplify a fixed post because they involve movement from one area to another, rather than remaining stationary. Therefore, the only correct representation of a fixed post in the context provided is the role of working at a front desk.