Acetaldehyde cyanohydrin on hydrolysis gives

A compound X gives cyanohydrin with HCN and the cyanohydrin on hydrolysis yields lactic acid. The compound X is

Acetaldehyde cannot give

Compound 'A' undergoes formation of cyanohydrin which on hydrolysis gives lactic acid [CH_(3)CH(OH)COOH] Therefore, compound 'A' is :

Compound 'A' undergoes formation of cyanohydrin which on hydrolysis gives lactic acid [CH_(3)CH(OH)COOH] Therefore, compound 'A' is :

Acetaldehyde cannot give: