Which of the following processes would you predict to have an increase in entropy?

a. condensation of water

b. freezing water

c. melting ice

d. deposition of CO2 (changing from a gas to solid)

C. Melting ice.

It is C because melting ice is a change of state from solid to liquid which requires an addition of energy (or entropy) into the system.

Condensation of water occurs from a gas to a liquid state, which takes energy out of the system (water) and gives it to the surroundings (air around it). Freezing water is the same as condensation except for the state change. Deposition is simply gas to a solid instantaneously so you can again see it as with the other two examples.