Charlie is at an amusement park that has 18 different rides. Each ride costs $1.75. The function C(r) = 1.75r represents the total amount of money that Charlie will spend if he goes on r rides, but he never goes on the same one more than once. What domain and range are reasonable for the function? A. D : 1 ≤ r ≤ 18 R : 1.75 ≤ C(r) ≤ 31.5 B. D : 0 ≤ r ≤ 18 R : 18 ≤ C(r) ≤ 31.5 C. D : 0 ≤ r ≤ 31.5 R : 0 ≤ C(r) ≤ 18 D. D : 0 ≤ r ≤ 18 R : 0 ≤ C(r) ≤ 31.5