When a 5 GHz HT station in a 40 MHz BSS desires to protect a 40 MHz transmission from an OFDM
station using an RTS/CTS or CTS-to-Self exchange, what frame format is used for the RTS and/or CTS
frames?

A.
HT-mixed format

B.
HT-greenfield format

C.
Dual-CTS

D.
Non-HT Duplicate

E.
Phased Coexistence PPDU