System a and system b are each in thermal equilibrium with system c. according to the zeroth law of thermodynamics, systems a and b must be separated by an insulator
in contact with a source of heat
at different temperatures
in thermal equilibrium with each other

i think the correct answer from the choices listed above is option c. when the kinetic energy of particles in a liquid state decreases

explanation:

no. bullets are macro objects. wave nature is for light waves, extremely tiny particles. if a light particle was the size of your finger, the bullet would be the size of the universe. so basically, that huge difference in size makes the wave nature of matter insignificant.