Solar energy is the correct answer. Two of the processes that make up the water cycle need solar energy and these include:
1. Transpiration- as plants absorb water from the soil, the soil, the water moves through the stem to the leaves . Once the water reaches the leaves , some of it evaporates from the leaves, adding to the amount of water vapor in the air. This process of evaporation from the leaves is known as transpiration and requires warmth of the sun (heat energy) to make temperatures jut right for it to take place
2. Evaporation- water that has returned to earth through precipitation and found in rivers, lakes, sea, and ponds when heated by the sun's thermal (solar) heat energy evaporates and as water vapor rises again into the atmosphere.