The correct answer is D. benzoic acid.
Benzoic acid is a preservative that is used to prevent the growth of bacteria and fungi in food. It is found naturally in some fruits and berries, but it is also produced synthetically. Benzoic acid is approved by the U.S. Food and Drug Administration (FDA) for use in a variety of foods, including jams, jellies, pickles, and soft drinks.
Acetylene is a gas that is used in welding and cutting. It is also used to produce other chemicals, such as acetaldehyde and acetic acid. Acetylene is not approved for use in food processing.
Sodium carbonate is a base that is used in a variety of applications, including cleaning, manufacturing, and food processing. In food processing, sodium carbonate is used as a leavening agent, a buffering agent, and a pH regulator. It is also used to remove calcium from water.
Sodium nitrate is a salt that is used in a variety of applications, including fertilizer, explosives, and food processing. In food processing, sodium nitrate is used as a preservative and a color fixative. It is also used to cure meat.
Benzoic acid is the only substance listed that is approved for use in food processing. It is a safe and effective preservative that can help to prevent the growth of bacteria and fungi in food.