Which of the following has the lowest freezing point?

Given: Molar mass of $C$,$H$,$O$,$Cl$ are $12$,$1$,$16$ and $35.5 \text{ g mol}^{-1}$,respectively. Statement $I$: In $30\%$ (w/w) solution of methanol in $CCl_4$ (at $T \text{ K}$),the mole fraction of $CCl_4$ is equal to $0.33$. Statement $II$: Mixture of methanol and $CCl_4$ shows positive deviation from Raoult's law.

$20\%$ of acetic acid is dissociated when its $5\ g$ is added to $500\ mL$ of water. The depression in freezing point of such water is $..... \times 10^{-3} \ { }^{\circ}C$. Atomic mass of $C$,$H$,and $O$ are $12$,$1$,and $16 \ \text{a.m.u.}$ respectively.
[Given: Molal depression constant and density of water are $1.86 \ K \ kg \ mol^{-1}$ and $1 \ g \ cm^{-3}$ respectively.]

The freezing point of an aqueous solution is $-0.186^oC$. If the molal elevation constant and molal depression constant of the solvent are $0.512$ and $1.86$ respectively,then the elevation in boiling point is .......... $^oC$.

If the mole fraction of the solvent decreases while preparing a solution,then ...........

$W \ g$ of a non-volatile electrolyte solid solute of molar mass $M \ g \ mol^{-1}$ when dissolved in $100 \ mL$ water,decreases vapor pressure of water from $640 \ mm \ Hg$ to $600 \ mm \ Hg$. If aqueous solution of the electrolyte boils at $375 \ K$ and $K_b$ for water is $0.52 \ K \ kg \ mol^{-1}$,then the mole fraction of the electrolyte solute $(X_2)$ in the solution can be expressed as (Given density of water $= 1 \ g/mL$ and boiling point of water $= 373 \ K$):