With which of the following compounds does aniline react to form a Schiff base?

For the following diazonium ions,the order of reactivity towards diazo-coupling with phenol in the presence of dilute $NaOH$ is:
$(I)$ $p-Me_2N-C_6H_4-N_2^+$
$(II)$ $p-O_2N-C_6H_4-N_2^+$
$(III)$ $p-CH_3O-C_6H_4-N_2^+$
$(IV)$ $p-CH_3-C_6H_4-N_2^+$

Given below are two statements:
Statement $I$: Aniline is less basic than acetamide.
Statement $II$: In aniline,the lone pair of electrons on nitrogen atom is delocalised over benzene ring due to resonance and hence less available to a proton.
Choose the most appropriate option:

The increasing order of $pK_b$ values of the following compounds is

Treatment of ammonia with excess of ethyl chloride will yield

On heating an aliphatic primary amine with chloroform and ethanolic potassium hydroxide,the organic compound formed is: