Which of the following solutions will have the lowest vapour pressure

Solution                    net concentration               0.1M Glucose                 0.1 X 1=0.1               0.1M NaCl                      0.1 X 2=0.2               0.1M BaCl2                    0.1 X 3=0.3               0.1m Al2(SO4)3              0.1 X 5=0.5As LVP increases VP  decreases order of VP is (1)>(2)>(3)>(4)