I believe the correct answer is the last option. When atoms get excited, atoms would release a particular color of light. When atoms gets excited, the electrons would move from a lower level to a higher level. However, this state is only short-lived and happens only in a split second then it goes back to its original level immediately. Going back to the lower level would release some extra amount of energy which is being released as heat or, oftentimes, as light in the form of electromagnetic energy or the particle photons. Thus, it releases a specific color of light depending on the wavelength of the light.
