Which two statements offer evidence that the clocks energy is conserved?

A. Conservation of energy happens only when the parts of a conquer world to reduce friction

B. Conservation of energy occurs because the clocks matter is also conserved

C. Friction between us moving parts transform some of the pendulum mechanical energy into forms of energy (I already know this is one option)

D. The pendulum stops moving because all of its mechanical energy has been transforming to thermal energy and sound energy