A wild horse runs at a rate of 8 miles for 6 hours. Let f(x) be the distance in miles, the horse travels for a given amount of time, x, in hours. This situation can be modeled by a function. What is the domain of the function?
a. 0 < x < 6
b. 0 < f(x) < 6
c. 0 < x < 48
d. 0 < f(x) < 48
