What recommendation will have the greatest mitigation on the effects of 802.11b clients on the rest of the network?

After interviewing the customer to understand its wireless client requirements, you determine that
802.11b must be enabled to support legacy clients within a mixed-mode environment. What
recommendation will have the greatest mitigation on the effects of 802.11b clients on the rest of
the network?

A.
Restrict the use of OFDM modulation.

B.
Make 11 Mb/s the lowest mandatory rate.

C.
Enable a separate SSID for 802.11b clients.

D.
Enable short preamble.