For \[C{H_3}COOH\] is a
A.Reducing agent
B.Dehydrating agent
C.Drying agent
D.Pickling agent

Hint: Acetic acid is the organic acid with a molecular formulae \[C{H_3}COOH\] . Though, it is a weak acid but in the concentrated form, it is corrosive in nature and can produce burns on coming in contact with the skin.

Complete answer:
Acetic acid is a carboxylic acid in which the methyl group is attached to the carboxyl group. Its IUPAC name is ethanoic acid.
The \[{H^ + }\] group present in the acetic acid is responsible for the acidic nature and it helps to ionise the compounds.
\[C{H_3}COOH \leftrightarrow C{H_3}CO{O^ - } + {H^ + }\]
So, we can see from the above equation that it releases anion and hydrogen cation or ions and this hydrogen ion plays a very important role. It helps to adjust the pH of the solutions.
This property of ethanoic acid is used as a pickling agent. It helps us to maintain the pH of the solution by adjusting the \[{H^ + }\] ions and makes it suitable for the pickles to be stored or made at their best.
So, from the above discussion, we can easily tell that our correct option is D i.e. ethanoic acid, \[C{H_3}COOH\] is used as the pickling agent.

Note:
The acetic acid is formed by the reaction of carbon-monoxide with the methanol i.e. the process is known as carbonylation of methanol. Acetic acid is the colourless liquid but with a characteristic pungent smell that makes it detectable. In the undiluted solutions, it is known as glacial acetic acid because of its appearance as ice. Actually it precipitates as crystals at a temperature below \[{16.6^o}C\] . Ethanoic acid also has a wide range of applications – it is used in polar solvents and glacial acetic acid is used to estimate the alkaline substances.