avoid Layer 2 loops. Which two of the following are most probably the reasons for that preference?（）

• A、Information about port roles is sent to all switches.
• B、RSTPs that are based on Cisco products require no additional configuration.
• C、Features such as UplinkFast and BackboneFast are compatible with RSTP.
• D、An RSTP that is based on Cisco products generally performs better than the Cisco proprietary 802.1D enhancements.