Question: Ana rolled her wagon down the ramp to reach the playground. There, she and her sister played on the seesaw. Which set of simple machines has Ana used?

  Options: 
 A. Lever, pulley, and wedge
 B. Pulley, inclined plane, and screw
 C. Wedge, wheel and axle, and screw
 D. Wheel and axle, inclined plane, and lever
Answer: D