The answer to this is letter C. It is evident that H already has the overlying deposit. From M going to F, there is an obvious shift of the rock layers due to erosion. Erosion is known to be one of the common problems that the environment is facing right now. It is not only rocks that are being eroded but also soil.
This can be a problem because when soil becomes eroded, the plants, trees, and shrubs that are rooted in the soil also die. With the lack of greenery, there are more environmental hazards that may be felt. Not having enough plants and trees can cause certain areas to be hotter. There is also a higher chance of experiencing floods because of erosion.