To solve this problem, we need to identify the major products P, Q, and R in the given reaction sequence.$\newline$The sequence involves:$\newline$1. Friedel-Crafts Alkylation:$\newline$• Benzene reacts with $CH_3CH_2CH_2Cl$ in the presence of anhydrous $AlCl_3. \newline$• This is a Friedel-Crafts alkylation reaction, where the propyl group $(CH_2CH_2CH_3)$ is added to the benzene ring.$\newline$• The product P is propylbenzene.$\newline$2. Oxidation of Alkylbenzene:$\newline$• Propylbenzene undergoes oxidation with $O_2$ and $H_3O^+/\Delta. \newline$• The side chain is oxidized to a carboxylic acid, resulting in benzoic acid (Q).$\newline$• The remaining part of the side chain is oxidized to acetone (R).$\newline$Analyzing the options:$\newline$• Option 1: Incorrect products.$\newline$• Option 2: Incorrect products.$\newline$• Option 3: Incorrect products.$\newline$• Option 4: Correct products.$\newline$Therefore, the correct option is Option 4.$\newline$P: Propylbenzene $(C_6H_5CH_2CH_2CH_3) \newline$Q: Benzoic acid $(C_6H_5COOH) \newline$R: Acetone $(CH_3COCH_3)$