D. a globe :) sorry if this didn't help!!
Water is highly valuable in Eastern and South Africa because it is too expensive for the government to afford in a time of drought. Therefore, when they build water pumping stations to provide them with enough water, they need to place the wells in a specific location that is easily accessible for the local people to travel to and get enough for their family that is sufficient enough to last them the whole day.
The answer to the question is the total surface area increases and chemical composition changes. Consider the breakdown of rock into smaller pieces, these fragments vary from huge rocks to smaller sizes. As they are so crushed and broken they tend to occupy much of the surface area than when its just a huge rock.