Which of the following amines is the weakest base?

Which of the following is the strongest base?

Which of the following is the weakest base?

Determine the order of basic strength for the following compounds:

What is the physical state of pure aniline?

Assertion : Nitration of aniline can be conveniently done by protecting the amino group by acetylation.
Reason : Acetylation increases the electron density in the benzene ring.