132. A system where a user authenticates, is disconnected, and the receiving system connects back to a number in a pre-defined database is also known as which?

Вариант ответа 1 - A. Callback

Вариант ответа 2 - B. Call forward

Вариант ответа 3 - C. Remote Access

Вариант ответа 4 - D. Port knocking