An employee is on an elevator, and a stranger asks where the employee works and who the network administrator is. This is an example of:

Eavesdropping is secretly listening to a private conversation without the consent of those involved, which is not directly what the stranger is doing by actively asking questions.

Social engineering is a manipulation technique that exploits human error to gain private information, access, or valuables. In this scenario, the stranger is attempting to trick the employee into revealing sensitive company information without authorization.

Dumpster diving is sifting through trash to find information, which is unrelated to a direct verbal interaction with an employee.

An on-path attack (formerly man-in-the-middle) is when an attacker secretly relays and alters the communication between two parties, which is a network-based attack, not a direct verbal psychological manipulation.