Which water-cycle process naturally removes dissolved salts and many non-volatile impurities from water by changing liquid water into vapour?

Correct answer: Evaporation driven by solar energy

The correct answer is B: solar-energy-driven evaporation. Sunlight supplies energy to liquid water at seas, lakes, rivers, and wet soil. Water molecules then escape into the atmosphere as vapour. Most dissolved salts and other non-volatile substances do not enter the vapour phase, so they remain in the original water body or become concentrated there. Later, condensation and precipitation return water to Earth, making the overall process similar to natural distillation. A and C mainly move water across the land and do not purify it by phase change. D is leaching: water dissolves and carries substances through soil, so it may increase the dissolved load rather than remove it. The word “fully” should not be understood as removing every possible pollutant, especially volatile contaminants; evaporation primarily separates water from salts and non-volatile impurities.