STD 11 - 3. Classification of elements and periodicity in properties — NEET STD 11 Science — Question

$\begin{array}{*{20}{c}}
  {\,\,\,\,\,C{H_3}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} \,\,\,\,\,{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} O{\mkern 1mu} } \\ 
  {\,\,\,|{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} \,\,\,\,\,\,\,\,\,\,{\mkern 1mu} {\mkern 1mu} ||} \\ 
  {C{H_3} - CH - C - OH} 
\end{array}$ $+ C{H_3} - N{H_2} \to 'A'\xrightarrow[\Delta ]{}'B'\xrightarrow{\begin{subarray}{l} 
  {\text{LiAl}}{{\text{H}}_4} \\ 
  {\text{(excess)}} 
\end{subarray} }'C'$ 

The final product $‘C’$ will be

$(A)$ Upon heating, $H _3 PO _3$ undergoes disproportionation reaction to produce $H _3 PO _4$ and $PH _3$.

$(B)$ While $H _3 PO _3$ can act as reducing agent, $H _3 PO _4$ cannot.

$(C)$ $H _3 PO _3$ is a monobasic acid.

$(D)$ The $H$ atom of $P - H$ bond in $H _3 PO _3$ is not ionizable in water.