You manage a WLAN with 100 802.11ac access points. All access points are configured to use 80 MHz channels. In a particular BSS, only 40 MHz communications are seen. What is the likely cause of this behavior?

A. The short guard interval is also enabled.

B. The clients are all 802.11n STAs or lower

C. The AP is improperly configured to use only 40 MHz of the 80 MHz allocated bandwidth

D. All clients implement single spatial stream radios