$$ \text { Given below are two statements : } $$

$$ \text { Statement I : } $$ and are two anomers of D-(+)-glucode.

Statement II : The open chain forms of D-glucose and D- fructose contain three similar chiral carbons at $\mathrm{C}_3, \mathrm{C}_4$ and $\mathrm{C}_5$.

In the light of the above statements, choose the correct answer from the options given below :

A paper dipped in a dil. $\mathrm{H}_2 \mathrm{SO}_4$ solution of ' $X$ ' upon treatment with $\mathrm{SO}_2$ gas turns into green. The compound ' $X$ ' is :

The total number of unpaired electrons present in the $d^3, d^4$ (low spin) $d^5$ (high spin), $\mathrm{d}^6$ (high spin) and $\mathrm{d}^7$ (low spin) octahedral complex systems is $\_\_\_\_$ .

RMgI when treated with ice cold water liberated a gas which occupied $1.4 \mathrm{dm}^3 / \mathrm{g}$ at STP. The gas produced is further reacted with iodine in presence of $\mathrm{HIO}_3$ to give compound $(\mathrm{X})$. Compound $(\mathrm{X})$ in presence of Na and dry ether produced compound $(\mathrm{Y})$. Molar mass of compound $(\mathrm{Y})$ is $\_\_\_\_$ $\mathrm{g} \mathrm{mol}^{-1}$. (Nearest integer)