The major product$(s)$ obtained from the following reaction of $1 \ mole$ of hexadeuteriobenzene $(C_6D_6)$ is/are:

Which of the following has the lowest knocking property?

$C_6H_6 + CH_3Cl \xrightarrow{anhydrous \ AlCl_3} C_6H_5CH_3 + HCl$ is an example of

Which of the following has the most stable enol form?

During the mixed acid nitration of benzene,concentrated $HNO_3$ behaves like:

The reaction sequence is as follows:
$1,4-dibromocyclohex-2-ene$ $\xrightarrow[{2 \, molar \, equivalent}]{{(CH_3)_2NH}} (A)$ $\xrightarrow{{BaO}} (B)$ $\xrightarrow[{ (2 \, molar \, equivalent) }]{{CH_3I}} (C)$ $\xrightarrow{{Ag_2O \, / \, H_2O}} (D) + 2(CH_3)_3N$
Identify the end product $(D)$ in the given sequence.