Answer:
Condensation
Step-by-step explanation:
That's the definition.
Condensation is the conversion of a gas to a liquid.
A. is wrong. Melting is the conversion of a solid to a liquid.
B. is wrong. Sublimation is the conversion of a solid to a gas.
D. is wrong. Evaporation is the conversion of a liquid to a gas.
The picture below shows the condensation of water vapour on window glass on a cold winter day.