But-2-yne and hydrogen (one mole each) are separately treated with (i) $\mathrm{Pd} / \mathrm{C}$ and (ii) $\mathrm{Na} /$ liq. $\mathrm{NH}_3$ to give the products X and Y respectively.

Identify the incorrect statements.

A. X and Y are stereoisomers.

B. Dipole moment of $X$ is zero.

C. Boiling point of X is higher than Y .

D. X and Y react with $\mathrm{O}_3 / \mathrm{Zn}+\mathrm{H}_2 \mathrm{O}$ to give different products.

Choose the correct answer from the options given below :

$$ \text { The final product }[\mathrm{B}] \text { is : } $$

Consider the following reaction :

The product Y formed is :

The dibromo compound $[\mathrm{P}]$ (molecular formula: $\mathrm{C}_9 \mathrm{H}_{10} \mathrm{Br}_2$ ) when heated with excess sodamide followed by treatment with dilute HCl gives [Q]. On warming [Q] with mercuric sulphate and dilute sulphuric acid yield $[R]$ which gives positive Iodoform test but negative Tollen's test. The compound $[\mathrm{P}]$ is :