A souvenir shop sells special mugs at a price of 15 each, and at that price, a total of 450 mugs are sold per month. The store manager estimates that for every 1 increase in the price of the mug, 18 fewer mugs will be sold per month. If the price of the mug increases by x dollars, which of the following functions best models the estimated monthly revenue R(x) , in dollars, generated from selling the mugs? (The revenue generated from selling the mugs can be found by multiplying the price of the mug by the number of mugs sold.)

A) R(x)= (15)(450) - (x)(18x)
B) R(x)= (15+x) (450 - 18x)
C) R(x)= (15-18x) (450 + x)