Assertion: For calculating the molality or the mole fraction of solute, if the molarity is known, it is necessary to know the density of the solution.
Reason: Molality, molarity and the mole fraction of solute can be calculated from the weight percentage and the density of the solution.
A. (a)If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. (b)If both assertion and reason are true and the reason is not the correct explanation of the assertion.
C. (c )If the assertion is true but reason is false.
D. (d)If assertion is false but reason is true.