Which of the following has the lowest knocking property?

Assertion : Benzene removes a butter stain from a table cloth.
Reason : Butter has an affinity towards benzene.

Given below are two statements:
Statement $I$: Nitration of benzene involves the following step:
$H-O^+(H)-NO_2 \rightleftharpoons H_2O + NO_2^+$
Statement $II$: Use of Lewis base promotes the electrophilic substitution of benzene.
In the light of the above statements,choose the most appropriate answer from the options given below:

Among the given compounds,which one is not aromatic?

In pyrrole,the electron density is maximum on

The major product of the given reaction is: