Which feature allows clients to perform Layer 2 roaming between wireless controllers?

Mobility groups allow wireless LAN controllers to share client context information, enabling clients to perform seamless Layer 2 roaming between Access Points (APs) associated with different controllers within the same mobility group, without requiring reauthentication or new IP address assignment.

N+1 high availability is a redundancy model for controllers to ensure uptime and failover, not a mechanism for enabling client Layer 2 roaming between active controllers.

RF grouping is a feature used for coordinating Radio Resource Management (RRM) among APs to optimize channel and power settings, and does not directly facilitate client Layer 2 roaming between controllers.

SSO (Single Sign-On) provides a unified authentication experience for users across multiple applications or services, but it is not the network feature that enables Layer 2 roaming for wireless clients between controllers.