INSIGHT UPSC QUIZ

ANS. (A) 
An artesian well is a pump less water source that uses pipes to allow underground water that is under pressure to rise to the surface. This type of well seems to defy gravity because the pressure that builds up between layers of rock gets relieved when the water finds a path to the open air. In addition, the water has been naturally filtered because it passes through porous rock as it seeps into the Earth to reach the aquifer, which is the underground water source. For centuries, people have drilled artesian wells to drink filtered water that doesn’t need to be manually or mechanically hauled up from the depths.