The final cost of a bookstore purchase with a $5 coupon in a state that charges 8% sales tax is given by the expression. The variable x represents the amount of the purchase before the sales tax and the coupon is applied.

1.08(x−5)

What does (x−5) represent?

A.the rate at which the total cost increases

B.the total charge before applying sales tax

C.the total charge after tax

D.the cost before applying the coupon