During the association, the client and AP agree to use the same transmit rate, but either station can request a change at any time after the association.

The client and AP each choose the optimal data rate to use independently of one another, based on their own measurements related to the RF link.

The client and AP may use different transmit rates, but the AP determines the data rate that will be used by each client station in the BSS.

The client and AP may use different transmit rates, but the client determines the data rate that it will use and the data rate that the AP will use when communicating to the client.

The client and AP may use a different transmit rates, but the transmit rate is determined by the peer station, based on the peer’s experience of the RF link.