Six-year-old students at an elementary school were given a 20-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. ) 6 ≤ x ≤ 60, or x is from 6 to 60
B.) 6 ≤ x ≤ 20, or x is from 6 to 20
C.) 0 ≤ x ≤ 20, or x is from 0 to 20
D.) 20 ≤ x ≤ 60, or x is from 20 to 60