Which of the following processes releases heat? evaporation freezing melting sublimation . i know for sure it is not freezing.

During freezing heat will be released. Normally we wont think like that ,but the reality is during freezing the heat get released. the liquid water will have more energy than the frozen water .so during this transition the energy of the water get released as the latent heat. Basically when we need to reduce the temperature ie. freezing a substance, the heat already absorbed in the substance should be released out of the substance.