What must visitors do when they arrive on federal property?

When visitors arrive on federal property, it is crucial for them to follow the lawful direction of federal law enforcement. This requirement is in place to ensure the safety and security of the premises, as well as to maintain order. Federal law enforcement officers are trained to assess situations, enforce regulations, and manage any potential security threats. Adhering to their instructions helps facilitate a safe environment for all individuals on the property, ensuring compliance with policies established for public safety.

The other options do not reflect the primary responsibility of visitors on federal property. For example, complying with requests from other visitors does not necessarily pertain to security protocols or lawful directions that protect everyone. Signing in at the front desk may be a procedural step, but it does not encompass the critical aspect of responding to law enforcement's commands. Similarly, waiting for a tour guide is unrelated to security regulations and might not even apply in all contexts where visitors find themselves on federal grounds. Overall, recognizing and respecting the authority of federal law enforcement is key to maintaining security and compliance on federal property.