What are the three major states of North America?

According ti the following map, what are the most common mineral resources found in the united states?

17. the soil erosion pictured here is the result of what? a. harvesting renewable resources at a rate greater than the sustainable yield b. a mudslide caused by excessive rains c. harvesting renewable resources at a rate lower than the sustainable yield d. the transition between geologic eras and eons

What is an additional type of erosion found at the coast? what does it mean?