To solve this problem, we need to analyze the reactions given in the question:$\newline$1. The first reaction is: $3ROH + PCl_3 \rightarrow 3RCl + A \newline$2. The second reaction is: $ROH + PCl_5 \rightarrow RCl + HCl + B \newline$Let's break down each reaction to identify the products A and B.$\newline \newline$1. Reaction of alcohol with $PCl_3: \newline$• When alcohol (ROH) reacts with phosphorus trichloride (PCl_3), it forms an alkyl chloride (RCl) and phosphorous acid (H_3PO_3).$\newline$• The balanced equation is: $3ROH + PCl_3 \rightarrow 3RCl + H_3PO_3 \newline$• Therefore, product A is $H_3PO_3. \newline \newline$2. Reaction of alcohol with $PCl_5: \newline$• When alcohol (ROH) reacts with phosphorus pentachloride (PCl_5), it forms an alkyl chloride (RCl), hydrochloric acid (HCl), and phosphoryl chloride (POCl_3).$\newline$• The balanced equation is: $ROH + PCl_5 \rightarrow RCl + HCl + POCl_3 \newline$• Therefore, product B is $POCl_3. \newline \newline$Based on the analysis, the products A and B are $H_3PO_3$ and $POCl_3$ respectively.$\newline$This corresponds to Option 2.