When compared with legacy Power Save mode, how does VHT TXOP power save improve battery life for devices on a WLAN?

A. VHT TXOP power save allows stations to enter sleep mode and legacy Power Save does not.

B. VHT TXOP power save allows the WLAN transceiver to disable more components when in a low power state.

C. VHT TXOP power save uses the partial AID in the preamble to allow clients to identify frames targeted for them.

D. Legacy Power Save mode was removed in the 802.11ac amendment.