Colligative properties of a solution depend upon

Consider $0.1 \ M$ solutions of two solutes $X$ and $Y$. The solute $X$ behaves as a univalent electrolyte while the solute $Y$ dimerises in solution. Which of the following statements are correct regarding these solutions?
$(a)$ The boiling point of the solution of $X$ will be higher than that of $Y$
$(b)$ The osmotic pressure of the solution of $X$ will be higher than that of $Y$
$(c)$ The freezing point of the solution of $X$ will be lower than that of $Y$
$(d)$ The relative lowering of vapour pressure of both the solutions will be the same
Select the correct answer from the given options $:-$

Identify the colligative property from the following options.

Assertion : The water pouch of an instant cold pack for treating athletic injuries breaks when squeezed and $NH_4NO_3$ dissolves,lowering the temperature.
Reason : Addition of a non-volatile solute into a solvent results in the depression of the freezing point of the solvent.

Match the items given in Column-$I$ (method used for determining colligative property) and Column-$II$ (the corresponding colligative property) and find the correct order.

Column-$I$	Column-$II$
$A$. Beckmann method	$1$. Osmotic pressure
$B$. Ostwald-Walker method	$2$. Elevation in $B$.$P$.
$C$. Berkeley-Hartley method	$3$. Depression in $F$.$P$.
$D$. Landsberger method	$4$. Relative lowering of vapour pressure

Which of the following is not a colligative property?