To maintain communication while working alone, you should:

Maintaining communication while working alone is crucial for ensuring safety and prompt assistance in case of emergencies. Utilizing a phone to check in with coworkers is an effective strategy to enhance safety. This practice establishes regular contact with a team or supervisor, allowing for real-time updates on your well-being and any work-related developments. It creates a support network that can respond quickly if you don't check in as scheduled, thereby providing an extra layer of security.

The other choices, while they may pertain to safety in certain contexts, do not directly address the need for ongoing communication while working alone. Requesting an escort in parking lots does not effectively solve the issue of isolation once you are alone at your work site. Testing a burglar alarm, meanwhile, is more about securing the premises than ensuring that you have communication established for personal safety during your shift. Thus, regular check-ins via phone is the best practice in this situation.