Which of the following processes is spontaneous?
1. The reversible isothermal expansion of an ideal gas
2. The vaporization of superheated water at 102°C and 1 bar
3. The constant pressure melting of ice at its normal freezing point by the addition of an infinitesimal quantity of heat
4. The adiabatic expansion of a gas into a vacuum
A) 3 only
B) 1 and 4 only
C) 2 and 4 only
D) 1, 2, and 4 only
E) All are true