Which of the following will have the highest freezing point $(F.P.)$ at one atmosphere?

$x$ moles of $CO(NH_2)_2$ are present in $1200 \ g$ of water. If the freezing point of the solution is $-4.02 \ ^oC$,calculate the value of $x$. Given $k_f \ (H_2O) = 1.86 \ K \ kg \ mol^{-1}$.

What is the cryoscopic constant of water if $5 \ g$ of glucose in $100 \ g$ of water causes a depression in freezing point of $2.15 \ K$? (Molar mass of glucose $= 180 \ g \ mol^{-1}$)

An aqueous solution contains $5\%$ by weight of urea and $10\%$ by weight of glucose. The freezing point of the solution is .......... $^oC$. [ $K_f$ for $H_2O$ is $1.86 \ K \ kg \ mol^{-1}$ ]

$A$ solution of $36 \ g$ of glucose $(C_6H_{12}O_6)$ in $1000 \ g$ of water is cooled to $-0.5 \ ^\circ C$. How many grams of ice would have separated from the solution? (Given: $K_f = 1.86 \ K \ kg \ mol^{-1}$)

$1.00 \ g$ of a non-electrolyte solute dissolved in $50 \ g$ of benzene lowered the freezing point of benzene by $0.40 \ K$. The ${K_f}$ for benzene is $5.12 \ K \ kg \ mol^{-1}$. The molecular mass of the solute will be ............ $g \ mol^{-1}$.