Answer:
Option B, The neutral nature of water changes due to mixing of various salts, bases, and acids, thus changing its pH.
Explanation:
Water obtained from natural sources like underground water, sea water, rain water etc are not neutral in nature. This is so because water extracted from all these sources contains several dissolved salts/chemical components which either reduces or increases their pH.
The ground water contains lot of dissolved carbonates and bicarbonates (as it remains in contact of rocks beneath the earth) due which it becomes extremely hard and has a pH greater than 7. On the other hand rain and snow water are acidic in nature and have a pH between 5 to 6.
Thus, it is only due to the dissolved bases and acids in natural water which makes it either acidic or basic in nature.