In which reaction does the organic compound undergo oxidation?
- A$\text{CH}_3\text{CH}_2\text{OH}$ + concentrated $\text{H}_3\text{PO}_4$
- B$\text{CH}_3\text{CH}_2\text{CH}_2\text{CHO}$ + Tollens’ reagent
- C$\text{CH}_3\text{COCH}_3$ + 2,4-dinitrophenylhydrazine reagent
- D$\text{CH}_3\text{CN}$ + dilute $\text{H}_2\text{SO}_4$