Explanation:

- Grapes contain several types of acids which contribute to their flavor and preservation.

- Malic acid (Option 2) is naturally found in grapes. It gives them a tart taste.

- Tartaric acid (Option 3) is also present in grapes. It plays a key role in maintaining their acidity.

- Citric acid (Option 4) is present in smaller amounts in grapes, less than tartaric and malic acids.

- Acetic acid (Option 1) is not naturally present in fresh grapes, but it can form during fermentation or spoilage.

So, you are highlighting the correct option. Option 1: Acetic acid is the correct answer. .