Reaction of thionyl chloride with white phosphorus forms a compound [A], which on hydrolysis gives [B], a dibasic acid. [A] and [B] are respectively.
\( \mathrm{PCl_3} \) and \( \mathrm{H_3PO_3} \)
\( \mathrm{P_4O_6} \) and \( \mathrm{H_3PO_3} \)
\( \mathrm{PCl_5} \) and \( \mathrm{H_3PO_4} \)
\( \mathrm{POCl_3} \) and \( \mathrm{H_3PO_4} \)