Boiling point of benzene is 353.23 K. When 1.8 g of non-volatile solute is dissolved in 90 g of benzene, boiling point is raised to 354.11 K. If Kb (benzene):2.53 kg mol-1 the molecular mass of non-volatile substance is
(a) 58 g mol-1
(b) 120 g mol-1
(c) 116 g mol-1
(d) 60 g mol-1