Assertion: Nitration of benzene with nitric acid requires the use of concentrated sulphuric acid. 

Reason: The mixture of concentrated sulphuric acid and concentrated nitric acid produces the electrophile, ${\mathrm{NO}}_2^{+}$

Assertion is false but Reason is true.

Assertion is true but the Reason is false

Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Both Assertion and Reason are true but Reason is not a correct explanation of the Assertion.