Among the following, the solution which exhibits least colligative property is

Colligative property depends upon no. of particles and concentration.

$\mathrm{Concentration}\left(\mathrm{C}\right)=\frac{\mathrm{no}.\mathrm{of} \mathrm{moles}\left(\mathrm{n}\right)}{\mathrm{Volume}\left(\mathrm{V}\right)}$

$\mathrm{C}=\frac{\mathrm{n}}{\mathrm{V}}\Rightarrow \mathrm{n}=\mathrm{c}\times \mathrm{v}$

A) 500 ml, 0.1 M

$\mathrm{n}=0.1\times 500\mathrm{ml}=0.1\times \frac{1}{2}\left(\mathrm{lit}\right)=0.05$

B) 250 ml,0.5 M

$\mathrm{C}=\frac{1}{4}\times 0.5=0.125\left[250\mathrm{ml}=\frac{1}{4}\mathrm{lit}\right]$

$\mathrm{C}) 1000\mathrm{ml}=1\mathrm{lit}$

$$\begin{gathered} \mathrm{n}=\mathrm{c}\times \mathrm{v} \\ =0.02\times 1=0.02 \end{gathered}$$

$\mathrm{n}=\mathrm{C}\times \mathrm{V}=1\times 0.5-0.5$

(C) has less no .of moles $\to$ less no .of particles $\to$ least colligative property .