The molar mass of acetic acid dissolved in benzene determined from the depression in freezing point is found to be

Question

$\begin{array}{1 1} 30\;g\;mol^{-1} \\ 60\;g\;mol^{-1} \\ 120\;g\;mol^{-1} \\ 240\;g\;mol^{-1} \end{array} $