Which of the Following Statements Is/are True

Which of the following statements is/are true?

A) With the demand-oriented method, prices are based on what customers expect or are willing to pay.
B) The keystone method of setting price involves doubling the cost of the merchandise to obtain the initial retail selling price.
C) Under the cost-oriented method, the retail price is determined by adding a fixed percentage to the cost of the merchandise.
D) All of these statements are true.
E) None of these statements are true.