The Standard Enthalpy Change of Fusion and Vaporization for Water

The standard enthalpy change of fusion and vaporization for water are +6.01 kJ mol^-1 and +40.7 kJ mol^-1 respectively. Why is the value for vaporization so much larger than fusion?

A) Because it is measured at a higher temperature.
B) Because the pressure has increased.
C) Because gas is released into the surroundings.
D) Because overcoming all intermolecular forces that hold a liquid together needs a lot of energy.