In an Organized Sales Dialogue (Presentation,)the Salesperson's Ability to Develop

In an organized sales dialogue (presentation,) the salesperson's ability to develop a customized solution is heavily dependent upon:

A) The salesperson's ability to listen during needs discovery.
B) The salesperson's ability to speak convincingly.
C) The buyer's ability to articulate his/her needs.
D) The salesperson's ability to use visual aids
E) Both a and d