The relationship between osmotic pressure at  $273 \mathrm{K}$ when $10 \mathrm{g}$ glucose $\left(P_1\right) , 10 \mathrm{g}$ urea $\left(P_2\right)$ and $10 \mathrm{g}$ sucrose $\left(P_3\right)$ are dissolved in $250 \mathrm{mL}$ of water is

We know that the osmotic pressure is given by $\Pi =\mathrm{iMRT}$ 

where

$\mathrm{i}$ is the Van't Hoff factor

$\mathrm{M}$  is the molarity 

$\mathrm{R}=0.08206 \mathrm{L}-{\mathrm{atmmol}}^{-1}{ \mathrm{K}}^{-1}$is the gas constant 

$\mathrm{T}$ is the absolute temperature

$\Pi \propto \mathrm{M}$

Molarity is inversely proportional to molecular weight.

Molecular weight of glucose $=180g$,

urea $=60g$ 

sucrose $=342g$

Osmotic pressure is also inversely proportional to molecular weight.

Therefore, osmotic pressure of $\mathrm{urea}> \mathrm{glucose} >\mathrm{sucrose}$.

$P_1=$ Osmotic pressure of glucose $(10 \mathrm{g})$

${\mathrm{P}}_2=$ Osmotic pressure of urea $(10 \mathrm{g})$

${\mathrm{P}}_3=$ Osmotic pressure of sucrose $(10 \mathrm{g})$

So, ${\mathrm{P}}_2>{\mathrm{P}}_1>{\mathrm{P}}_3$

Hence, option(c) is correct