Answer: B. Electrolysis of water forming hydrogen and oxygen
Explanation:
I believe it would be B. Electrolysis of water forming hydrogen and oxygen since melting ice is simply just a physical change from a solid to a liquid, shaping an iron rod into a horseshoe is also a physical change since it is still the same material just in a different shape, and evaporation of water is again also a physical change since it is changing its physical state.