The graph represents the money collected at the movie theater on Saturday. Find the domain when the maximum number of people allowed in the movie theater is 50 people.
A. 40 ≤ x ≤ 140
B. 0 ≤ y ≤ 50
C. 40 ≤ y ≤ 140
D. 0 ≤ x ≤ 50