The figure shows an accelerometer: a device for measuring the horizontal acceleration of cars and airplanes. The device consists of a ball that is free to roll on a parabolic track. A scale along the bottom is used to measure the ball's horizontal position x. What is the acceleration of the car in m/s² when the displacement of the ball in the accelerometer equals 0.20 m?
(a) 3.9
(b) 3.6
(c) 26.5
(d) 24.5
(e) 9.1