# Which one of the following is the ratio of the lowering of vapour pressure of 0.1 m aqueous solutions of $BaCI_2, NACI\: and \: AI_2(SO_4)_3$ respectively ?

$\begin {array} {1 1} (1)\;3:2:5 & \quad (2)\;5:2:3 \\ (3)\;5:3:2 & \quad (4)\;2:3:5 \end {array}$