Which enhancement was introduced in 802.11 ac Wave 2 and was not present in 802.11n?

Which enhancement was introduced in 802.11 ac Wave 2 and was not present in 802.11n?
A . 64 QAM
B . 128 QAM
C . SU-MIMO
D . 40 MHz channel width
E . four spatial streams
F . MU-MIMO

View Answer

Answer: F

Explanation:

Reference: http://www.cisco.com/c/en/us/solutions/collateral/enterprise-networks/802-11ac-solution/q-and­a-c67-734152.html