The telephone operator is responsible for providing wake-up calls to guests. They are usually part of the front office and handle phone-related services.
- Receptionist is a key figure in managing guest check-ins and check-outs but typically does not handle wake-up calls directly.
- Informationist refers to a person who handles guest inquiries but is not typically involved in providing wake-up calls.
- Concierge assists with special guest requests and arrangements but does not generally handle wake-up calls.
Thus, the correct answer is Telephone operator.