A curling iron manufacturer has revenue and cost functions, both in dollars, given by R(x) = 50x - 0.1x² and C(x) = 5x + 3000, respectively, where x is the number of curling irons made and sold. What is the profit function?
a) P(x) = 45x - 0.1x² - 3000
b) P(x) = 45x - 0.1x² + 3000
c) P(x) = 55x - 0.1x² - 3000
d) P(x) = 55x - 0.1x² + 3000