Which statement describes virtual SNR DN configuration and behaviour on a Cisco Communication Manager Express IOS router?
A. A virtual SNR DN is a DN that must be associated with multiple registered IP phones
B. Mid-calls on virtual SNR DN can be pulled back as soon as a phone becomes associated with the DN
C. SNR feature can only be invoked if the virtual SNR DN is associated with at least one registered IP phone
D. A call that is ringing a virtual SNR DN prior to its association with a registered phone, cannot be answered by the phone even after the association is made
E. Virtual SNR DN supports either SCCP or SIP IP phone DNs
