What are \(\mathrm{X}\) and \(\mathrm{Y}\) in the following reaction?
\(\mathrm{R}-\mathrm{OH}+\mathrm{PCl}_5 \rightarrow \mathrm{X}+\mathrm{Y}+\mathrm{HCl}\)

1. A \(\begin{array}{cc}
   \underline{\mathrm{X}} & \underline{\mathrm{Y}} \\
   \mathrm{R}-\mathrm{OCl} & \mathrm{PCl}_3 \\
   \end{array}\)
2. B \(\begin{array}{cc}
   \underline{\mathrm{X}} & \underline{\mathrm{Y}} \\
   \mathrm{R}-\mathrm{Cl} & \mathrm{POCl}_3 \\
   \end{array}\)
3. C \(\begin{array}{cc}
   \underline{\mathrm{X}} & \underline{\mathrm{Y}} \\
   \mathrm{R}-\mathrm{O}-\mathrm{R} & \mathrm{POCl}_3 \\
   \end{array}\)
4. D \(\begin{array}{cc}
   \underline{\mathrm{X}} & \underline{\mathrm{Y}} \\
   \mathrm{R}-\mathrm{Cl} & \mathrm{P}(\mathrm{OH})_3
   \end{array}\)