c
\(\mathrm{V} . \mathrm{P}\) of \(\mathrm{C}_{6} \mathrm{H}_{6}>\mathrm{V} . \mathrm{P}\) of \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{3}\)

\(\because \mathrm{YA}=\frac{\mathrm{P}^{\circ} \mathrm{A} \mathrm{X} \mathrm{A}}{\mathrm{P}}, \mathrm{YB}=\frac{\mathrm{P}^{\circ} \mathrm{BXB}}{\mathrm{P}}\)

\(\mathrm{X}_{\mathrm{A}}\) and \(\mathrm{X}_{\mathrm{B}}\) are same so mole fraction in vapour phase is directly proportional to the vapour pressure.