Final answer:
The investigation is designed to answer how the surface of a ramp affects the distance a toy car rolls, by comparing how sandpaper and wax paper influence the car's movement due to different frictional forces. Therefore correct option is B
Step-by-step explanation:
The investigation conducted by the students involved measuring the distance a toy car traveled after rolling down a ramp covered with sandpaper or wax paper can answer the question: How does changing the surface of a ramp affect the distance a toy car rolls? The surface of the ramp can affect the frictional forces acting on the toy car. A rough surface like sandpaper is likely to create more friction than a smooth surface like wax paper, potentially causing the car to travel a shorter distance. By analyzing the results, students can understand the relationship between the surface texture and the motion of the toy car.