The structures of $\mathrm{A}$ and $\mathrm{B}$ formed in the following reaction are : $\left[\mathrm{Ph}=-{\mathrm{C}}_6{\mathrm{H}}_5\right]$

Arrange the following conformational isomers of n-butane in order of their increasing potential energy:

The total number of monohalogenated organic products in the following (including stereoisomers) reaction is

$$\begin{gathered} \underset{(\mathrm{Simplest} \mathrm{optically} \\ \mathrm{active} \mathrm{alkene})}{\mathrm{A}} \underset{\left(\mathrm{ii}\right) {\mathrm{X}}_2/∆}{\overset{\left(\mathrm{i}\right) {\mathrm{H}}_2/\mathrm{Ni}/∆}{\to }} \end{gathered}$$

consider the above reaction, and choose the correct statement: