Which of the following compounds does not react with bromine in alkaline medium?

The end product $C$ of the following reaction is

$$\mathrm{C}_2 \mathrm{H}_5 \mathrm{NH}_2 \xrightarrow{\mathrm{HNO}_2} A \xrightarrow{\mathrm{PCl}_5} B \xrightarrow[\text { Alcohol }]{\mathrm{NH}_3} C$$

Which of the following amines is most basic in nature in aqueous phase?

Which of the following reaction of diazonium salt involves retention of diazonium group?