Which channel-group mode must be configuredd when multiple distribution interfaces connected to a WLC are...

Channel-group mode on.. Wireless questions require separating client association, RF design, AP mode, WLAN security, and controller policy. Cisco CCNA 200-301 v1.1 includes this under Network Access, where the expected skill is to identify the feature that actually creates the observed behavior or meets the configuration goal. The wording usually contains the decisive clue: a prefix length, a VLAN role, a protocol version, a wireless security standard, or a management-plane function. Incorrect answers usually confuse an encryption method with authentication, or a controller feature with a switchport feature. In an operational network, choosing the wrong option would typically cause failed connectivity, insecure management, poor wireless behavior, or incorrect forwarding. The selected answer matches the Cisco configuration model and is retained as the verified answer.