1gm of non-electrolyte solute dissolved in 50gm of benzene lowered the freezing point of benzene by 0.4 K. Freezing point depression constant of benzene is 5.12 K Kg/mol. The molar mass of solute is
A. 252 g/mol
B. 256g/mol
C. 262 g/mol
D. 356 g/mol