A city bus slows down and then stops to pick up a passenger. Then the bus accelerates to the speed limit and maintains that speed. Which is the best description of the buses kinetic energy?
A. The bus's kinetic energy increased from zero to a certain level and then stayed the same.
B. The bus's kinetic energy declined and it increased.
C. The bus's kinetic energy stayed the same.
D. The bus's kinetic energy declined to zero, then increased to a certain level and stayed the same.