Which of the Following Statements About Upgrading Is True

Which of the following statements about upgrading is true?

A) It is also called suggestion selling.
B) The objective of upgrading is to expand the seller's business by selling to the customer in ever larger quantities.
C) To upgrade a customer the salesperson must usually show that the initial purchase was not exactly what the customer needed.
D) Upgrading is crucial to sellers, because without it their customers might turn to other suppliers when they need new equipment.
E) All of the above statements about upgrading are true.