Which of the following compounds has the lowest bond dissociation energy for a $C-H$ bond?

The rate of $o-$nitration of the following compounds,$(I)$ toluene,$(II)$ $2-D-$toluene,and $(III)$ $2,6-D_2-$toluene,is in the following order:

Identify the nonbenzenoid aromatic compound from the following.

Among the following,reaction$(s)$ which give$(s)$ tert-butylbenzene as the major product is(are):

Total number of deactivating groups in aromatic electrophilic substitution reaction among the following is:
$-COOCH_3$,$-NHCOCH_3$,$-NHCH_3$,$-CN$,$-OCH_3$

Credit for the ring structure of benzene goes to