Which feature would be helpful to prevent wireless internet access from 1 of the 25 buildings?

Corporation XYZ has 25 buildings (with a total of 12000 employees) and would like to implement a
single SSID across their entire site. Which feature would be helpful to prevent wireless internet
access from 1 of the 25 buildings?

A.
AP groups

B.
AAA override

C.
WLAN override

D.
MAC filtering