Which Cisco IP Phone series should be recommended to a customer who wants a basic voice communication endpoint?

Which Cisco IP Phone series should be recommended to a customer who wants a basic voice
communication endpoint?

A.
Cisco 6900 Series

B.
Cisco 8900 Series

C.
Cisco 7900 Series

D.
Cisco 3900 Series

E.
Cisco 9900 Series

Explanation:

The Cisco Unified SIP Phone 3900 Series combines a simple, easy-to-use ergonomic design with
basic communications features.
Reference: http://www.cisco.com/en/US/products/ps7193/index.html