A tent rental company charges a mandatory $125 setup fee and a $90 hourly rental fee. Which of the following equations can be used to find c, the cost of renting a tent from this company for 9 hours?
A. c = (125 + 90)9
B. c = 125 + 90(9)
C. c = 125 - 90(9)
D. c = 125(9) + 90