One substance contributing to the distinctive smell of burnt sugar is the compound below: $\text{CH}_3\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\rightarrow$ (the structure shows $\text{CH}_3\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\rightarrow$ $\text{CH}_3\text{COCHO}$) This compound has two functional groups. Which reagent reacts with only one of the functional groups?
- Aacidified potassium dichromate(VI)
- B2,4-dinitrophenylhydrazine
- Chydrogen cyanide
- Dsodium hydroxide