Which product is a network module for Cisco 2600XM Series Multiservice Routers, the Cisco 2691 Multiservice Platform, Cisco 2800 Series Integrated Services Routers, Cisco 3700 Series Multiservice Access Routers, and Cisco 3800 Series Integrated Services Routers and provides integrated, entry-level voice mail and auto attendant for the branch office?

A.
Cisco CallManager

B.
Cisco CallManager Express

C.
Cisco Unity

D.
Cisco Unity Express