We know that the heat of vaporization of water is 2260 J/g. So 100 gram sample of water being completely vaporized needs 2260*100=2.26*10^5 J. So the answer is (4).
the hot fire is depositing heat directly on to the marshmello, heating/cooking it. the hot marshmello then is placed onto chocolate, melting it but idk if that part matters.
