The correct answer is A. DMO is configured individually for each SSID in use in the network.

DMO is a feature that allows the AP to convert multicast streams into unicast streams over the wireless link. This enhances the quality and reliability of streaming video, while preserving the bandwidth available to the non-video clients. DMO is configured individually for each SSID in use in the network, as different SSIDs may have different multicast requirements.

According to the Aruba documentConfiguring WLAN Settings for an SSID Profile, one of the steps to configure DMO is:

Dynamic multicast optimization: Select Enabled to allow IAP to convert multicast streams into unicast streams over the wireless link. Enabling Dynamic Multicast Optimization (DMO) enhances the quality and reliability of streaming video, while preserving the bandwidth available to the non-video clients.

The other options are incorrect because:

B. The AP does not use QoS to provide equal air time for multicast traffic. QoS is a feature that prioritizes different types of traffic based on their importance and latency sensitivity. QoS does not affect how multicast streams are transmitted over the wireless link.

C. DMO is not configured globally for each SSID in use in the network. DMO is configured individually for each SSID, as different SSIDs may have different multicast requirements.

D. The controller does not convert multicast streams into unicast streams. The AP does the conversion, as it is closer to the wireless clients and can optimize the transmission based on the client capabilities and channel conditions.