The elements $\text{X}$ and $\text{Y}$ form compound having molecular formula $\mathrm{X}{\mathrm{Y}}_2$ and $\mathrm{X}{\mathrm{Y}}_4$ (both are non-electrolyses). When dissolved in $\text{20}\text{g}$ benzene, $\text{1}\text{g}$ $\mathrm{X}{\mathrm{Y}}_2$ lowers the freezing point by $\text{2}{\text{.3}}^{\text{o}}\text{C}$ whereas $\text{1}\text{g}$ of $\mathrm{X}{\mathrm{Y}}_4$ lowers the freezing point by $\text{1}{\text{.3}}^{\text{o}}\text{C}$. Molal depression constant for benzene is $\text{5}\text{.1}$. Thus atomic masses of $\text{X}$ and $\text{Y}$ respectively are

• A

  42.64, 21.10
• B

  21.10, 42.64
• Correct answer
  C

  25.59, 42.64
• D

  42.64, 25.69

Hence, the correct answer is option: 'C'.