Assertion: Pure water obtained from different sources always contains hydrogen and oxygen in the ratio of 1 : 8 by mass.
Reason: Molecular mass of water is 18.

A. Assertion and reason both are correct statements and reason is correct explanation for assertion.
B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C. Assertion is correct statements but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement.