Kb Values are a measure of basicity. Higher the Kb value, greater will be basicity.
(I) Basic character \alpha \frac{1}{%\text{ s- character}}
N−sp2 has more % s-character than N−sp3 so it is less basic as compare to N−sp3 Hence III>I.
(II) In the (ii) structure lone pair present on the N atom is involved in aromaticity so, it is difficult to donate. Hence, least basic
Thus, the correct order will be: III>I>II
