Which functional group is represented by the condensed formula -COOH?

1. In -COOH a carbon is double-bonded to one oxygen and single-bonded to an -OH. 2. This C(=O)-OH combination is the carboxylic acid functional group. 3. Rule out B: an aldehyde is -CHO, where the carbonyl carbon holds a hydrogen, not -OH. 4. Rule out C: an alcohol is just -OH, with no C=O present. 5. Rule out D: a ketone is -CO- flanked by two carbons, with no -OH. 6. Only carboxylic acid has both the C=O and the -OH on the same carbon. _Source: Balbharati (Maharashtra Board) Class 10 Science & Technology, Ch 9 "Carbon Compounds", p.127_