Consider the following.

Assertion (A) : CO is poisonous to living beings.

Reason (R) : CO binds to haemoglobin forming carboxyhaemoglobin, which is less stable than oxygen-haemoglobin complex.

Correct answer is

$$ \begin{aligned} &\text { Consider the following reaction sequence }\\ &\text { Vinyl benzene } \xrightarrow[\Delta]{\mathrm{KMnO}_4+\mathrm{KOH}} X \xrightarrow[\Delta]{\mathrm{NaOH}+\mathrm{CaO}} Y \end{aligned} $$

$' Y$ ' can also be formed from

$$ \text { The IUPAC name of the following compound is } $$

Gold crystallises in fcc lattice. The edge length of the unit cell is $4 \mathop {\rm{A}}\limits^{\rm{o}}$. The closest distance between gold atoms is ' $x$ ' $\mathop {\rm{A}}\limits^{\rm{o}}$ and density of gold is ' $y$ ' $\mathrm{g} \mathrm{cm}^{-3}$. What are $x$ and $y$ respectively?

(Molar mass of gold $=197 \mathrm{~g} \mathrm{~mol}^{-1} ; N=6 \times 10^{23} \mathrm{~mol}^{-1}$ )