A compound 'A' ( C_2 H_4 O ) on oxidation gives 'B' ( C_2 H_4 O_2). 'A' undergoes Iodoform reaction to give yellow precipitate and reacts with HCN to…

A = Acetaldehyde / $\displaystyle \mathrm{CH_3CHO}$ B = Ethanoic acid / $\displaystyle \mathrm{CH_3COOH}$ C = Acetaldehyde cyanohydrin / $\displaystyle \mathrm{CH_3CH(OH)CN}$$\displaystyle \mathrm{CH_3CHO}$ (A) $\displaystyle \xrightarrow{[\mathrm{O}]}$ $\displaystyle \mathrm{CH_3COOH}$ (B)$\displaystyle \mathrm{CH_3CHO}$ (A) $\displaystyle \xrightarrow{\mathrm{I_2\ NaOH}}$ $\displaystyle \mathrm{CHI_3}$ (Yellow ppt)$\displaystyle \mathrm{CH_3CHO}$ (A) $\displaystyle \xrightarrow{\mathrm{HCN}}$ (C) (C) $\displaystyle \xrightarrow{\mathrm{H_2O/H^+}}$