What layer of the OSI/ISO model does Point-to-point tunneling protocol (PPTP) work at?

A.
Data link layer

B.
Transport layer

C.
Session layer

D.
Network layer

Explanation:
PPTP works at the data link layer.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 708