Here's a problem to solve: Juan and LaKeisha roll a few objects down a ramp. They want to see which object rolls the farthest. What should they do so they can repeat their investigation?

Among the 4 following options, which is the correct answer?

- A: Put the objects in groups.
 
- B: Change the height of the ramp.
 
- C: Choose different objects to roll.
 
- D: Record the details of the investigation.
 