The purest form of water that is considered to be
Rainwater
Explanation for correct option:
Option (C) Rainwater
Purest form of water:
Explanation for incorrect options:
Water from well, bore water, as well as tap water, is not considered pure water as they contain certain ions as well as minerals while rainwater is free from minerals as it directly comes from rain.
Thus options A, B, and D are incorrect.
Hence, the correct option is (C).