$(i)$ મિથાઇલએમાઈન $(ii)$ ફોસ્જિન
$(iii)$ ફોસ્ફિન $(iv)$ ડાયમિથાઇલએમાઈન
$A\,and\,C\,\xrightarrow{{{\text{Diazotization}}}}\,P + Q\,\xrightarrow[{(ii)\,oxidation\,\left( {KMn{O_4} + {H^ + }} \right)}]{{{\text{(i) Hydrolysis}}}}$$\begin{array}{*{20}{c}} {R\left( {product\,of\,A} \right)} \\ { + \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {s\,\left( {prosuct\,of\,C} \right)} \end{array}$