Millions of years ago, the area pictured was the site of a mountain range. today, a few plateaus are all that remain. what can be said about the remaining rock forms? a. only the weakest portions of the rock remain. b. due to a lack of rainfall in the area, rain is not a factor in the erosion process. c. the rock has been worn down due to continental drift. d. the remaining forms consist of the hardest rock. re