Which of the following is the strongest base?

In the given reaction,what is the structure of the major product $X$?

Why does acetylation of $-NH_2$ group of aniline reduce its activating effect?

The correct statements about the products $B$ and $C$ in the given reactions are
$CH_3CH_2OH$ $\xrightarrow[\text{Anhy } ZnCl_2]{HCl} A$ $\xrightarrow[\text{AgCN}]{\text{ethanolic}} \underset{\text{Minor}}{B} + \underset{\text{Major}}{C}$
$I$. $B$ and $C$ are functional isomers
$II$. With $H_2 / \text{Catalyst}$,$B$ gives $1^{\circ}$ amine and $C$ gives $2^{\circ}$ amine
$III$. $B$ on acid hydrolysis gives formic acid and $C$ gives $C_3H_6O_2$
$IV$. $C$ forms isocyanate with $HgO$

Which of the following will be the most stable diazonium salt $(R-N_2{^+} X^{-})$?

Which of the following amines does not evolve $N_2$ gas upon reaction with $HNO_2$?