The acetylation of ethylamine gives $......$.

Given below are two statements:
Statement $I$: Benzenediazonium salt is prepared by the reaction of aniline with nitrous acid at $273-278 \ K$. It decomposes easily in the dry state.
Statement $II$: Insertion of iodine into the benzene ring is difficult and hence iodobenzene is prepared through the reaction of benzenediazonium salt with $KI$. In the light of the above statements,choose the most appropriate answer from the options given below:

What is the correct order of basicity for the substituted anilines ($I$ to $IV$)?

Which of the following will not give the Hoffmann bromamide reaction?

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

Identify the reagent $R$ in the following reaction:
$C_6H_5NO_2 \xrightarrow{R} C_6H_5NHOH$