By default，on the wlan controller for a voice application using cisco 7921 wireless ip phones.
what is the percentage of rf bandwidth that can be dedicated to the phones？（）

A.clients connected to the rogue access point must be able to connect to the containment controller-based access point.
B.multiple controller-based access points will load-balance the containment task using fewer resources than a single access point.
C.clients connected to the rogue access point may be out of the range of the controller-based access point providing containment.
D.each controller-based access point can handle only a limited amount of clients connected to the rogue access points.

A.c1130-k9w7-tar.boot
B.c1130-k9w7-tar.123-7.ja1.tar
C.c1130-k9w7-tar.default
D.c1130-k9w7-tar.recover

A.problem management
B.configuration management
C.incident management
D.change management