Wilscy owns a toy store. The number of toy trains sold (in thousands) from 2000 through 2005 can be modeled by M(x) = −0.5x3 + 2x2 − x + 9. The average cost per toy train (in dollars) can be modeled by N(x) = 0.3x + 7, where x represents the number of years since 2000. The total revenue Wilscy made by the sale of toy trains is the product of the number of toy trains sold and the average cost per toy train. Identify a polynomial P(x) that can be used to model the total revenue. Options:
a: P(x) = −0.15x4 − 2.9x3 + 13.7x2 − 4.3x + 63
b: P(x) = −0.5x3 + 2x2 − 0.7x + 2
c: P(x) = −0.15x4 + 4.1x3 + 14.3x2 − 9.7x + 63
d: P(x) = −0.5x3 + 2x2 − 1.3x + 16