Let us first give a formal definition of the terms.
1. Potential Energy: Energy that has the ability to do work, but is stationary at the moment.
2. Kinetic Energy: The energy of an object in motion.
Now that we know the definitions of these terms, we can answer the question. Remember that the area of greatest potential energy is that spot where there is potential to do work, but that energy is not causing any movement at the current time. The spot where there is the greatest amount of potential energy in the image is at the top of the roller coaster. There is little movement at this juncture, but there is plenty of potential energy. As the coaster goes down, the kinetic energy goes up, since the coaster is now in motion. The spot where there is the greatest amount of kinetic energy is near the bottom of the roller coaster.
