What is a good way to introduce HP Lync Solutions into a conversation with a customer?

A.
by asking the customer to identify the specific features of their PBX phone system they like most

B.
by finding out if the customer is satisfied with their current PBX provider

C.
by asking the customer how they plan to address the obsolescence of their legacy PBX

D.
by asking about additional features the customer would like to see included in their PBX