Wired Equivalent Privacy (WEP) operates at what layer of the OSI model?

A.
Physical

B.
Network

C.
Transport

D.
Data link

Explanation:

Working at the data link layer, WEP requires that all communicating parties share the same secret key. To avoid conflicting with U.S export controls that were in effect at the time the standard was developed, 40-bit encryption keys were required by IEEE 802.11b, through many vendors now support the optional 128-bit standard.
Reference: Cisco Courseware page 10-15