Answer:
A. the sun
Step-by-step explanation:
Water cycle -
Water cycle represents that , the evaporation process of the water from the surface of the Earth , and as it rises in to the atmosphere and then condense down and comes back to the surface of Earth , in the form of rain , snow fall .
The very first step , i.e. , the evaporation of the water , is done with the help of the energy of sun .
Because , sun provide the energy to convert the water to water vapor .