Which of the following groups is an ortho and para directing group?

In chlorobenzene,the $-Cl$ group is deactivating; however,it still undergoes electrophilic aromatic substitution reactions. Column-$(I)$ contains the reagents and Column-$(II)$ contains the products. Match Column-$(I)$ with Column-$(II)$.
| Column-$(I)$ (Reagents) | Column-$(II)$ (Products) |
| :--- | :--- |
| $(A)$ $Cl_2$ / anhydrous $AlCl_3$ | $(i)$ $1$-chloro-$2$-methylbenzene + $1$-chloro-$4$-methylbenzene |
| $(B)$ conc. $HNO_3$ + conc. $H_2SO_4$ | $(ii)$ $2$-chlorobenzenesulfonic acid + $4$-chlorobenzenesulfonic acid |
| $(C)$ conc. $H_2SO_4$ and heat | $(iii)$ $1,2$-dichlorobenzene + $1,4$-dichlorobenzene |
| $(D)$ $CH_3COCl$ in presence of anhydrous $AlCl_3$ | $(iv)$ $2$-chloroacetophenone + $4$-chloroacetophenone |
| | $(v)$ $1$-chloro-$2$-nitrobenzene + $1$-chloro-$4$-nitrobenzene |

Identify $[A]$,$[B]$,and $[C]$,respectively in the following reaction sequence $:$

Which one of the following is least reactive in a nucleophilic substitution reaction?

Arrange the following groups in increasing order of reactivity towards electrophilic nitration reaction: $C_6H_6, C_6H_5Cl, C_6H_5COOH, C_6H_5NH_2$.

$A$ solution of cyclohexene in benzene is stirred at $0 \ ^oC$ while concentrated sulphuric acid is added. After washing away the acid and removing the excess benzene,what product is isolated?