The diagram shows the different models of the atom that eventually led to the modern atomic theory. Four diagrams are shown labeled Model A, Model B, Model C, Model D from left to right. The diagram labeled Model A has a small sphere with a positive sign on it. This small sphere at the center is surrounded by a shaded circle. The shaded circle has negative signs placed randomly inside it. The diagram labeled Model B is a large solid sphere. The diagram labeled Model C has a sphere at the center and a dotted cloud around the sphere. The dotted cloud is dense near the sphere and becomes faint as we move away from the sphere. The diagram labeled Model D has a sphere surrounded by three concentric circles. Each concentric circle has some spheres on it. Which model is based on Bohr's quantum model? Model A Model B Model C Model D