Question

why does all matter contain thermal energy?
because particles stop moving
because particles can never stop moving
because all matter is cold
because all matter is hot

Explanation:

Thermal energy is related to the motion of particles. According to the kinetic theory of matter, particles are in constant motion. If particles stopped moving (absolute zero, which is not achievable in practice for all matter), there would be no thermal energy. Matter isn't all cold (as cold is relative and even cold matter has some particle motion) and not all matter is hot. The key is that particles are always in motion (to some extent above absolute zero, which is a theoretical limit), so matter has thermal energy due to particle motion.

Answer:

Because particles can never stop moving