c
The key functional groups present in a typical carbohydrates are the hydroxyl group \((-\mathrm{OH})\) and the carbonyl group \((>\mathrm{C}=\mathrm{O})\) made up of the ketone group \((>\mathrm{C}=\mathrm{O})\) or the aldehyde group \((-\mathrm{HC}=\mathrm{O})\)