Which two statements about the implementation of WLAN QoS are true？（）

A.The 802.11e standard is the IEEE 802.11 OoS WLAN standard.
B.The Wi-Fi Multimedia （WMM） standard decreases the eight priority levels to four access categories.
C.The Wi-Fi Multimedia （WMM） standard is a Wi-Fi Alliance standard that increases the four priority levels to eight access categories.
D.The Wi-Fi Multimedia （WMM） standard is an IEEE standard that increases the four priority levels to eight access categories.
E.Wireless 802.11 deploys Distributed Coordination Function （DCF）， carrier sense multiple access with collision detection （CSMA/CD）， interframe spacing， and random wait timers to avoid collisions.
F.Wireless OoS designs and implementations commonly use Layer 3 differentiated services code point （DSCP） or Layer 2 802.1 p to ensure priority