Identify the product '$$\mathrm{B}$$' in the following reaction. Toluene $$\xrightarrow[\mathrm{CS}_2]{\text { Chromylchloride }} \mathrm{A} \xrightarrow{\mathrm{H}_3 \mathrm{O}^{+}}\mathrm{B}$$

Which among the following is a simple ketone?

Which from following compounds is obtained when toluene is treated with $$\mathrm{CrO}_2 \mathrm{Cl}_2$$ in presence of $$\mathrm{CS}_2$$ followed by acid hydrolysis?

Which of the following is NOT prepared by the action of Grignard's reagent on methanal?