The correct order of reactivity towards elimination reaction:

$\left(\mathrm{i}\right)$ ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_2{\mathrm{CH}}_2-\mathrm{Br}$

$\left(\mathrm{ii}\right)$ ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2-\mathrm{Br}$

$\left(\mathrm{iii}\right)$ ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_2\underset{\mathrm{Br}}{\underset{|}{\mathrm{C}}}\mathrm{H}-{\mathrm{CH}}_3$

$\left(\mathrm{iv}\right)$ ${\mathrm{H}}_3\mathrm{C}-\underset{\mathrm{Br}}{\underset{|}{\mathrm{C}}}\mathrm{H}-{\mathrm{CH}}_3$

Major product of the given reaction : 

The correct statement regarding the comparison of staggered and eclipsed conformations of ethane is?

Product of following reaction is :-