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

Consider the following sequence of reactions. Total number of $sp^{3}$ hybridised carbon atoms in the major product $C$ formed is . . . . . . .

The order of basic strength of the following in aqueous solution is
$I$. $C_6H_5NH_2$
$II$. $(CH_3)_3N$
$III$. $NH_3$
$IV$. $CH_3NH_2$
$V$. $(CH_3)_2NH$

Which of the following products is a Schiff base?
$C_2H_5NH_2 \xrightarrow{HNO_2} a$
$C_2H_5NH_2 \xrightarrow{C_6H_5CHO} b$
$C_2H_5NH_2 \xrightarrow{NOCl} c$
$C_2H_5NH_2 \xrightarrow{C_6H_5SO_2Cl} d$

Given below are two statements :
Statement $I$: Aniline reacts with conc. $H_2SO_4$ followed by heating at $453-473 \ K$ to give $p$-aminobenzene sulphonic acid (sulphanilic acid). This compound contains both nitrogen and sulphur,and thus it gives a blood red colour in the 'Lassaigne's test' due to the formation of ferric thiocyanate,$[Fe(SCN)]^{2+}$.
Statement $II$: In Friedel-Craft's alkylation and acylation reactions,aniline forms a salt with the $AlCl_3$ catalyst. Due to this,the nitrogen atom of aniline acquires a positive charge and acts as a deactivating group,preventing further reaction.
In the light of the above statements,choose the correct answer from the options given below :

In the following reaction,the product $(A)$ is