What Types of Energy Are Utilized by a Child Swinging

Multiple Choice

What types of energy are utilized by a child swinging on a swing?

A) chemical energy only, because it is the child's metabolism that powers the muscles that make the swing move
B) kinetic, potential, and chemical energy: the child powers the swing with chemical energy in the muscle cells, and the swing moves like a pendulum with changing ratios of kinetic and potential energy
C) kinetic and potential energy only, but in constantly changing ratios: when changing direction, the energy is pure potential energy, but at the bottom of the arc, the energy is pure kinetic energy
D) kinetic energy only, because the child is in constant motion