Δh f° hints h f° is the enthalpy change when only the reactants are in their standard states. is the enthalpy change for the reaction that forms one gram of the compound from its elements with all substances in their standard states. is the enthalpy of fusion. is usually reported at 298k.

answer

fusion: the energy source of stars. the energy released from the collapse of the gas into a protostar causes the center of the protostar to become extremely hot. when the core is hot enough, nuclear fusion commences. fusion is the process where two hydrogen atoms combine to form a helium atom, releasing energy.

hope it

it is b that is the answer.