A new wireless client is configured to join a 802.11 network. This client uses the same hardware and software
as many of the other clients on the network. The client can see the network, but cannot connect. A wireless
packet sniffer shows that the Wireless Access Point (WAP) is not responding to the association requests being
sent by the wireless client.
What is a possible source of this problem?

A.
The WAP does not recognize the client’s MAC address

B.
The client cannot see the SSID of the wireless network

C.
Client is configured for the wrong channel

D.
The wireless client is not configured to use DHCP

Explanation:
MAC Filtering (or GUI filtering, or layer 2 address filtering) refers to a security access control method whereby
the 48-bit address assigned to each network card is used to determine access to the network. MAC Filtering is
often used on wireless networks.
https://en.wikipedia.org/wiki/MAC_filtering