Five-year-old students at an elementary school were given a 30-yard head start in a race. The graph shows how far the average student ran in 30 seconds.
Which statement best describes the domain of the function represented in the graph?
A. 5 ≤ x ≤ 60, or x is from 5 to 60
B. 5 ≤ x ≤ 30, or x is from 5 to 30
C. 30 ≤ x ≤ 60, or x is from 30 to 60
D. 0 ≤ x ≤ 30, or x is from 0 to 30