Sodium sodium salt of butanoic acid is subjected to decarboxylation in presence of soda lime?

Which hydrogen in compound $\left(E\right)$ is easily replaceable during bromination reaction in presence of light ?

Isomers of hexane, based on their branching, can be divided into three distinct classes as shown in the figure.

The correct order of their boiling point is

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

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