Scientists Interested in Knowing the Best Way to Restore an Area

Scientists interested in knowing the best way to restore an area after a temporary road was built through it completed a study comparing two treatments: (1) restoring the contour of an area so that there was no longer a depression or cut-through where the road was previously and (2) simply abandoning the area to allow vegetation to return on its own. They wanted to know whether either or both of these treatments would return the aboveground vegetation and the belowground soil properties to their original state, as seen in a similar area where there had never been a road.
-Which statement best describes data that the scientists should collect and how they should be compared?

A) comparison of plant species in the recontoured area, the abandoned area, and the never-roaded area
B) comparison of properties of soil and plant species in the contoured area and abandoned area
C) comparison of soil properties and species of plants present in the contoured area with that of the never-roaded area; and that of the abandoned area with that of the never-roaded area
D) comparison of soil properties only among all three areas since soil properties will determine plant species