Identify $Z$ in the above sequence of reactions.

Which of the following does not have intermolecular hydrogen bonding?

Identify $A$ and $B$ in the following reaction sequence:
$C_6H_5NH_2 + CH_3COCl$ $\rightarrow A$ $\xrightarrow{Br_2/H_2O} B$

$RCOCl + 2Me_2NH \to A + Me_2NH_2^+Cl^-$. Here $A$ is:

$A$ hydrocarbon $A$ $(C_{4}H_{8})$ on reaction with $HCl$ gives a compound $B$ $(C_{4}H_{9}Cl)$ which on reaction with $1 \ mol$ of $NH_{3}$ gives compound $C$ $(C_{4}H_{11}N)$. On reacting with $NaNO_{2}$ and $HCl$ followed by treatment with water,compound $C$ yields an optically active compound $D$. The compound $D$ is

In the case of substituted aniline,the group which decreases the basic strength is