问题：

[单选] 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.