The correct answer is C) Esters.
Esters are derivatives of carboxylic acids and are commonly used as flavoring agents in various food and beverage products. They contribute to the pleasant aroma and taste of many fruits and other natural substances. Esters can be synthesized by reacting a carboxylic acid with an alcohol in the presence of an acid catalyst or enzyme, known as esterification.
Acid halides (option A), acid carbonyls (option B), and acid amides (option D) are also derivatives of carboxylic acids, but they are not typically used as flavoring agents. Acid halides and acid carbonyls are often used as intermediates in synthetic procedures or in the production of other chemicals. Acid amides, on the other hand, are commonly found in proteins and play important biological roles.
Therefore, the derivative of carboxylic acid that is specifically used as a flavoring agent is esters (option C).
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