Hello!
Your answer is A, the solar energy provides the energy for water to evaporate. (this energy being heat)
The reason for this is, the sun creates light, and with light comes heat. Heat causes water to evaporate into steam, and when it reaches higher points in the atmosphere, the pressure causes it to compress into what we call clouds. when these clouds become too large, They release the cooled steam as rain.
I hope this helps, and have a nice day!