Suggest the mechanism of the following reaction?

(i)

(ii)

(iii)

(iv)

(v)

; Here $\mathrm{X}$ and $\mathrm{Y}$ respectively are,

 ; Here $\mathrm{P}$ is

; most likely the compound $\left[\mathrm{X}\right]$ is

Suggest the product of the reactions:

When $\mathrm{A}$ (given below) reacts with $\mathrm{HI}$ products is $\mathrm{B}$ and not $\mathrm{C}.$ Explain.

Isotopic carbon$-14$ in $\left(\mathrm{A}\right)$ appears at new position (as in $\mathrm{B})$ when $\left(\mathrm{A}\right)$ reacts with ${\mathrm{CH}}_3\mathrm{ONa}.$ Explain.