What access control method uses the client's MAC address to permit access?

• A. MAC filtering
• B. WEP
• C. WPA
• D. RADIUS

Answer: (A)

MAC filtering is an access control method that permits or denies network access based on the device’s hardware address. In practice, the access point maintains a list of allowed (or blocked) MAC addresses; when a device attempts to connect, the AP checks its MAC against that list and lets it in if it matches. This makes it a simple form of control at the data-link layer, but it isn’t strong security because MAC addresses can be spoofed and it doesn’t provide encryption or robust user authentication. The other options serve different roles: WEP and WPA are encryption protocols for protecting traffic, while RADIUS is a centralized authentication server.