The Wi-Fi Multimedia (WMM) certification, created by the Wi-Fi Alliance, is based on the ___________ medium access method with support for ___________.

A.
HEMM, Block Acknowledgement

B.
EDCA, Transmission Opportunities

C.
HCCA, Unscheduled APSD

D.
DCF, Fast/Secure Roaming

E.
PCF, Registered Polling