Walter owns a small online business that makes and sells jewelry. The revenue function of Walter's small business can be shown by the function below, where x represents the number of days in business.
r(x)=x^{2}+10x-470
Which statement best describes the constant term?
A. a profit of $10 per jewelry piece sold
B. a daily profit of $470
C. a start-up cost of $470
D. a $10 cost of operation per day