Providing a Customer with Service After the Sale Is

Providing a customer with service after the sale is:

A) important,because it is a commitment to the buyer that cements a long-term relationship
B) important,because it gives the customer the illusion that the vendor is a larger company than it is
C) important,because these follow-up services can generate more revenue for the vendor
D) a luxury,because most salespeople are busy chasing new customers
E) a luxury,because no money is generated by providing follow-up service