A cereal company estimates that its monthly cost is
C(x) = 400x2 + 300x and its monthly revenue is
R(x) = -0.6x3 + 900x2 – 400x + 700, where x is in thousands of boxes sold. The profit is the difference between the revenue and the cost.

What is the profit function, P(x)?

A. P(x) = -0.6x^3 + 1300x^2 - 100x + 700
B. P(x) = 0.6x^3 - 500x^2 + 700x - 700
C. P(x) = -0.6x^3 + 500x^2 - 700x + 700
D. P(x) = 0.6x^3 - 1300x^2 + 100x + 700