Born Haber cycle is based on
 

Born Haber cycle is a cycle of enthalpy change of process that leads to the formation of a solid crystalline ionic compound from the elemental atoms in their standard state and of the enthalpy of formation of the solid compound such that the net enthalpy becomes zero.

Hence it is related to energy i.e., law of conservation of energy.

Hence, the correct option is option (B) Law of conservation of energy.