Which Cisco IP phone would be most appropriate for a customer who would like to have additional lines and speed dial buttons on their phone?

Which Cisco IP phone would be most appropriate for a customer who would like to have additional lines and speed dial buttons on their phone?

A.
Cisco IP Phone 7902G

B.
Cisco IP Phone 7910SW

C.
Cisco IP Phone 7914 Expansion Module

D.
Cisco IP Phone 7940