The reaction of a primary amine with an aldehyde gives $......$.

The product $(P)$ of the following reaction:

$CH_3NH_2 + CHCl_3 + 3KOH \rightarrow X + Y + 3H_2O$;
Compounds $X$ and $Y$ are:

The major product obtained in the following reaction is:

The increasing order of $pK_b$ for the following compounds will be:
$(A)$ $NH_2-CH=NH$
$(B)$ $1,5,7-Triazabicyclo[4.4.0]dec-5-ene$
$(C)$ $(CH_3)_2NH$

The compound $X$ $(C_7H_9N)$ reacts with benzenesulfonyl chloride to give $Y$ $(C_{13}H_{13}NO_2S)$ which is insoluble in alkali. The compound $X$ is