What action should workers take before entering a zoned facility after radio pharmaceutical treatment?

Workers should notify a supervisor before entering a zoned facility after radio pharmaceutical treatment because safety protocols are in place to protect both the individual and others in the facility. This step ensures that the supervisor can assess the situation, confirm that it is safe for the worker to enter, and manage any potential risks related to radiation exposure.

Notifying a supervisor also allows for appropriate monitoring and adherence to regulatory guidelines that govern access to areas where there could be radioactive materials present. The other options imply actions that could lead to safety risks, either by entering without proper communication, following others without assessing conditions, or waiting inappropriately in a restricted area. Prioritizing communication with a supervisor is essential in maintaining a safe working environment and adhering to established safety protocols.