What type of functional group would you find in a carboxylic acid?

In a carboxylic acid, the functional group present is indeed a combination of both a hydroxyl group and a carbonyl group. The carboxylic acid functional group is structured as –COOH, which consists of a carbonyl group (C=O) bonded to a hydroxyl group (–OH).

The carbonyl component gives the acid its ability to participate in reactions typical of aldehydes and ketones, such as nucleophilic addition reactions. Meanwhile, the hydroxyl part contributes to the acidic nature of carboxylic acids, allowing them to donate protons (H+ ions) in aqueous solutions. This combination of functional groups is what defines carboxylic acids and distinguishes them from other types of functional groups.

Thus, since both functional groups are integral to the structure of carboxylic acids, the correct answer accurately reflects this characteristic.