Assuming all the substances are already at the temperature that is their melting point, we only need to worry about the heat required to change state, not the heat required to change temperature.
No calculations necessary for this question - just look at the latent heat of fusion. The higher this value, the more heat required per unit mass of the substance to melt it. Of the four answer options, aluminum has the highest value and therefore will take the most heat to melt the same mass.
