The correct answer is A. Picric acid.
A carboxylic acid group is a functional group with the formula -COOH. It is a characteristic group of organic acids and occurs in many naturally occurring compounds. The carboxylic acid group is a polar group, and it is responsible for the acidic properties of carboxylic acids.
Picric acid is a yellow, crystalline solid with the chemical formula C6H3N2O5. It is a strong acid and is used as a dye, a reagent, and an explosive. Picric acid does not contain a carboxylic acid group.
Vinegar is a solution of acetic acid in water. Acetic acid is a carboxylic acid with the chemical formula CH3COOH. It is a weak acid and is responsible for the sour taste of vinegar.
Salicylic acid is a white, crystalline solid with the chemical formula C6H4(OH)CO2H. It is a carboxylic acid and is used as a pain reliever, an antipyretic, and an anti-inflammatory agent.
Benzoic acid is a white, crystalline solid with the chemical formula C6H5COOH. It is a carboxylic acid and is used as a preservative, a flavoring agent, and a sunscreen.