Final answer:
The first action a supervisor should take if uncertain about someone's official business on Transit Authority property is to ask for identification.
Step-by-step explanation:
If a supervisor is uncertain that a person who he does not know has official business on Transit Authority property, the first action that the supervisor should take is to ask for identification from the person. This is an important step to ensure the safety and security of the property and those on it. By asking for identification, the supervisor can determine if the person has a valid reason to be on the property.
For example, if the person provides appropriate identification such as an employee badge or a visitor's pass, it indicates that they have official business on the property and can be allowed to proceed. On the other hand, if the person fails to provide valid identification or gives inconsistent answers, the supervisor may need to take further action such as contacting security or law enforcement.