Which one is the weakest base?

Aniline reacts with which of these to form a Schiff base?

$A$ student has been given a compound $x$ of molecular formula $C_6H_7N$. $x$ is sparingly soluble in water. However,on addition of dilute mineral acid,$x$ becomes soluble in water. $x$ when treated with $CHCl_3$ and $KOH$ (alc.) produces $y$. $y$ has a specific unpleasant smell. On treatment with benzenesulphonyl chloride,$x$ gives a compound $z$ which is soluble in alkali. The number of different $H$ atoms present in $z$ is:

Identify $X$ and $Y$ in the following reactions:
$Nitrobenzene \xrightarrow{Zn/NH_4Cl} X$
$Nitrobenzene \xrightarrow{Zn + KOH/C_2H_5OH} Y$

Find the correct order of acidity of the following compounds:
$(I)$ $C_6H_5NH_2$
$(II)$ $C_6H_5CONH_2$
$(III)$ Phthalimide
$(IV)$ $CH_3CH_2NH_2$

Compound $A$ from the following reaction sequence is: