One of the Most Effective Ways a Marketer Can Reduce

One of the most effective ways a marketer can reduce the cost of personal selling is by

A) eliminating the need for database management by relying more on telemarketers.
B) communicating relevant product information before the sales call.
C) providing proof that what the salesperson says is factual.
D) reminding the prospect to close the sale quickly.
E) avoiding trial closes which are ineffective.