Which statements regarding an IEEE 802.11 Channel Switch Announcement frame are true?

A.
Channel Switch Announcement frames use the Action frame body format.

B.
Channel Switch Announcement frames are the only place where the Channel Switch Announcement element is found.

C.
Channel Switch Announcement frames must be transmitted immediately following a DTIM Beacon so that dozing stations will receive the channel switch information.

D.
Channel Switch Announcement frames carry information elements from an AP to a STA in a BSS.

E.
Channel Switch Announcement frames are transmitted after the wireless medium has been idle for a PIFS.