Answer: Option C
:
C
Rainwater is the purest form of natural water. Water from the water bodies such as lakes, ponds get evaporated leaving behind the impurities. The condensed water vapour is the most pure form of water among all the sources of natural water.
Underground is next only to rainwater in terms of purity. It contains dissolved impurities.
River and lake water contains dissolved impurities like salts, and insoluble impurities like clay, sand and living organisms (including microbes).
Therefore, the correct of purity from the given water sources is:
Lake water < Well water < Rainwater