When a member of a music club purchases one compact disk (CD) at the regular price, each additional CD maybe purchased at a 25 percent discount off the regular price. Which of the following expressions represent the amount, in dollars, that a member will pay for n CDs that have regular price of b dollars each ? A) b+n(b-0.25)
B) b+(n-1)(b-0.25)
C) b+0.25b(n-1)
D) b+0.75b(n-1)
E) b+0.75b(n)