Clouds release moisture on the of mountains.
a. windward side
b. leeward side
c. peaks
d. slopes

c. peaks

Clouds part of the hydrosphere release moisture at the peaks of mountains.
Hydrosphere includes the total mass of water on the surface, underground or over the surface of earth. About 75% of the earth’s surface are covered by oceans and so a huge part of our planet is covered in water and so hydrosphere is an important aspect. Hope I have answered your question as per your asking.