The graph represents the height of a basketball as a function of horizontal distance. The unit of measurement is feet. What is the best estimate for the interval where the function is decreasing?
A) When the basketball's horizontal distance was between 0 and 10 feet.
B) When the basketball's horizontal distance was between 5 and 11 feet.
C) When the basketball's horizontal distance was between 9 and 17 feet.
D) When the basketball's horizontal distance was between 11 and 17 feet.