Final answer:
The functional group not found in carbohydrates, in addition to an aldehyde, is an amine. Carbohydrates can contain aldehyde, ketone, and alcohol groups but not amines as they would categorize the compound differently.
Step-by-step explanation:
The functional group mentioned as not found in carbohydrates, in addition to an aldehyde, is amine. Carbohydrates typically consist of carbon, hydrogen, and oxygen atoms and must contain either an aldehyde (in aldoses) or a ketone (in ketoses) group along with multiple hydroxyl groups. The presence of an amine group would make a compound an amino compound or amide rather than a simple carbohydrate.
Regarding other options provided: ketone and alcohol groups can indeed be present in carbohydrates; ketones are found in ketoses, and alcohol (hydroxyl) groups are commonly found as part of the carbohydrate structure. On the other hand, esters are not typically functional groups that define carbohydrates, but they can be formed from carbohydrates through chemical reactions. Thus, the correct answer is d) Amine.