Which statement best describes clustering in a small-business wireless network？（）  

• A、 allows multiple access points to be connected wirelessly， without the need for a wired Ethernet network
• B、 replicates configuration parameters across access points in the cluster， while optimizing network performance
• C、 automatically configures wireless client devices via Wi-Fi Protected Setup
• D、 can get real-time traffic or bandwidth statistics from an access point within a cluster