Which of the following aqueous solutions has the highest freezing point?

Under identical conditions,which aqueous solutions have the same freezing point? (Molecular mass of urea $= 60 \ u$ and glucose $= 180 \ u$)

Identify $(i)$,$(ii)$ and $(iii)$ in the following diagram representing the depression in freezing point:

$2.7 \ kg$ of each of water and acetic acid are mixed. The freezing point of the solution will be $-x^{\circ} C$. Consider the acetic acid does not dimerise in water,nor dissociates in water. $x = . . . . . . .$ (nearest integer)
[Given : Molar mass of water $= 18 \ g \ mol^{-1}$,acetic acid $= 60 \ g \ mol^{-1}$]
$K_f \ H_2O = 1.86 \ K \ kg \ mol^{-1}$
$K_f$ acetic acid $= 3.90 \ K \ kg \ mol^{-1}$
Freezing point: $H_2O = 273 \ K$,acetic acid $= 290 \ K$

If $0.072 \ g-atom$ of sulfur is dissolved in $100 \ g$ of solvent $(K_f = 7.00)$,the depression in freezing point is $0.84 \ ^\circ C$. The molecular formula of sulfur in the solution is .............

$45 \ g$ of ethylene glycol $(C_{2}H_{6}O_{2})$ is mixed with $600 \ g$ of water. Calculate $(a)$ the freezing point depression and $(b)$ the freezing point of the solution.