Which of the following oil is obtained from benzene after fractional distillation of coal tar?

The $C - C$ bond length in benzene is ...... $\mathring{A}$.

$n-hexane$ $\xrightarrow{\text{catalyst}}$ benzene
The catalyst is:

Arrange the following compounds in increasing order of their reactivity towards electrophilic substitution:

$A$ compound $X$ formed after heating coke with lime reacts with water to give $Y$,which on passing over red hot iron at $873 \ K$ produces $Z$. The compound $Z$ is:

The following compound has four aromatic rings marked as $A$,$B$,$C$ and $D$. Rank them in terms of increasing reactivity towards electrophilic aromatic substitution?