Users report that the 802.11n wireless network is extremely slow. The network administrator
suspects that the problem is occurring because of a hidden node.
Which mechanism is a solution for this problem?

A.
Short Guard Interval (SGI)

B.
Reduced Inter-Frame Spacing (RIFS)

C.
CTS-to-Self

D.
Carrier sense multiple access with collision avoidance (CSMA/CA)