The osmotic pressure of a solution is directly proportional to

$A$ saturated solution of $Ag_2SO_4$ shows a $0.003 \ K$ rise in boiling point. Calculate the $K_{sp}$ of $Ag_2SO_4$. Given: $K_b = 5 \ K \ kg \ mol^{-1}$ and $1 \ m = 1 \ M$.

Identify the correct statements :
$(A)$ The molality of $2.5 \text{ g}$ of ethanoic acid (Molar mass : $60 \text{ g mol}^{-1}$) in $75 \text{ g}$ of benzene solution is $0.556 \text{ m}$.
$(B)$ The molarity of a solution containing $5 \text{ g}$ of NaOH (molar mass : $40 \text{ g mol}^{-1}$) in $450 \text{ mL}$ of solution is $0.278 \text{ M}$ at $298 \text{ K}$.
$(C)$ Aquatic species are more comfortable in cold water.
$(D)$ The solubility of gas increases with decrease in pressure.
$(E)$ For a binary mixture of $A$ and $B$, the number of moles of $A$ and $B$ are $n_{A}$ and $n_{B}$ respectively. The mole fraction of $B$ will be $x_{B} = n_{A} / (n_{A} + n_{B})$.
Choose the correct answer from the options given below :

In which solution,solute is liquid and solvent is gas?

An aqueous solution of urea:

At $T(K)$,the vapour pressure of pure benzene (molar mass $= 78 \ g \ mol^{-1}$) is $0.85 \ bar$. When $2.0 \ g$ of a non-volatile,non-electrolyte solute is added to $39 \ g$ of benzene,the vapour pressure of the solution at $T(K)$ is $0.83 \ bar$. The elevation in boiling point (in $K$) of the same solution is: ($K_b$ of benzene is $2.6 \ K \ kg \ mol^{-1}$)