An alcohol, $X\left(\mathrm{C}_5 \mathrm{H}_{12} \mathrm{O}\right)$ in the presence of $\mathrm{Cu} / 573 \mathrm{~K}$ gives $Y\left(\mathrm{C}_5 \mathrm{H}_{10}\right)$. The reactants required for the preparation of $X$ are

What are $X$ and $Y$ respectively in the following set of reactions?

$$ \text { Match the following } $$

$$ \begin{array}{llll} \hline & \text { List-I (Compound) } & & \text { List-II }\left(\mathrm{pK}_{\mathrm{a}}\right) \\ \hline \text { (A) } & \text { p-nitrophenol } & \text { (I) } & 15.9 \\ \hline \text { (B) } & \text { Phenol } & \text { (II) } & 7.1 \\ \hline \text { (C) } & \text { Ethanol } & \text { (IIII) } & 10.0 \\ \hline \text { (D) } & \text { p-cresol } & \text { (IV) } & 10.2 \\ \hline & & \text { (N) } & 8.3 \\ \hline \end{array} $$

The correct answer is

An alcohol $X\left(\mathrm{C}_4 \mathrm{H}_{10} \mathrm{O}\right)$ on dehydration gave alkene $\left(\mathrm{C}_4 \mathrm{H}_8\right)$ as major product, which on bromination followed by treatment with $Y$ gave alkyne $\mathrm{C}_4 \mathrm{H}_6$. Alkyne $\mathrm{C}_4 \mathrm{H}_6$, does not react with sodium metal. What are $X$ and $Y$ ?