Jane threw a basketball up in the air. The following table represents the height f(t), in meters, of the ball above the ground at time t seconds:
 Time (t)
 (in seconds) Height f(t)
 (in meters)
 2 10
 4 15
 6 10
 8 0
 Which of the following is represented by the x-intercept of f(t)?
 a. The ball reaches the maximum height in 4 seconds.
 b. The ball reaches a maximum height of 15 meters.
 c. The ball was thrown from a height of 10 meters.
 d. The ball touches the ground after 8 seconds.