Problem: Suppose compensation is given by W = 450,000 + 220p + 15S, where W = total compensation of the CEO, p = company profits (in millions) = $300, and S = Sales (in millions) = $500. What percentage of the CEO's total earnings is tied to profits of the firm?
A. 6.0%
B. 7.9%
C. 12.6%
D. 43.4%
Please show calculations.