In which of the following Person-to-Person social engineering attacks does an attacker pretend to be an outside contractor, delivery person, etc., in order to gain physical access to the organization?

In-person attack is an overly broad category descriptor, not a specific named social engineering technique.

Third-party authorization attack involves falsely claiming someone else has already approved an action, not assuming a physical identity.

Important user posing involves pretending to be a senior executive or high-privilege user to pressure staff, not an outside contractor.

Impersonation is the social engineering technique where an attacker adopts a believable false persona (contractor, vendor, delivery courier) to manipulate people into granting access. It is classified as a Person-to-Person attack because it relies on direct human interaction and deception rather than technical exploitation. The physical access dimension described in the question is a hallmark of impersonation attacks.