At a restaurant, diners earn 1 point for every $2 they spend, plus 25 bonus points on their first meal. Function f represents the number of points earned as a function of the total amount spent x. Which function represents the total amount spent as a function of the number of points earned? A. f^−1(x) = 2x − 50
B. f^−1(x) = 2x + 50
C. f^−1(x) = 0.5x − 50
D. f^−1(x) = 0.5x + 50