A 5.25% solution of a substance is isotonic with a 1.5% solution of urea (molar mass = 60 g $$mol^{-1}$$) in the same solvent. If the densities of both the solutions are assumed to be equal to 1.0 g $$cm^{-3}$$, molar mass of the substance will be

A

90.0 g $$mol^{-1}$$

B

115.0 g $$mol^{-1}$$

C

105.0 g $$mol^{-1}$$

D

210.0 g $$mol^{-1}$$