Why Is a Salesperson's Relationship with Each Business-To-Business Customer So

Why is a salesperson's relationship with each business-to-business customer so important?

A) A good salesperson focuses on all customers equally as a matter of integrity.
B) Each business-to-business customer represents a higher percentage of a salesperson's total business.
C) Each business-to-business customer is the source of referrals,and referrals are essential to building a sales business.
D) Customer retention policy states that salespeople must provide follow-up service as a way to increase customer satisfaction and increase the volume of sales.
E) If a salesperson does not maintain a good relationship with each customer,that customer may leave the company and tell others to leave the company as well,starting a domino effect.