None of the above
oxidation of acetaldehyde cyanohydrin
oxidation of formaldehyde cyanohydrin
oxidation of acetone cyanohydrin
Acetaldehyde with HCN gives acetaldehyde cyanohydrin
CH3CHO+HCN → CH3CH(CN)-OH
on oxidation it gives,
CH3CH(CN)-OH → CH3CH(OH)-COOH
CH3CH(OH)-COOH → CH3C(COOH)=O
gives pyruvic acid.