Which statement correctly describes a wireless client Layer 2 roam from AP1 to AP2 while joined to a multicast stream using Cisco WLC running v5.2?（）

• A、Client issues an IGMP join after association with AP2, allowing AP2 to request a multicast stream from  Cisco WLC after AP1 issues an IGMP query.
• B、Client issues an IGMP join after association with AP2, allowing AP2 to request a multicast stream from  Cisco WLC independent of AP1 multicast member status.
• C、Client resumes multicast after association with AP2,  because multicast information is sent in mobility  exchanges and AP2 is already a member of the multicast group,  provided that another client has  already joined that multicast.
• D、Client resumes multicast after association with AP2,  because multicast information is sent in mobility  exchanges and AP2 is already a member of the multicast group,  regardless if any other clients have  already joined that multicast.