Step 1: Define strong acids A strong acid is defined as a substance that fully ionizes in aqueous solution, yielding \( \text{H}^+ \) ions. Step 2: Identify the strong acid from the given choices - \( \text{H}_2\text{SO}_4 \) (sulfuric acid) is classified as a strong acid.- \( \text{CH}_3\text{COOH} \) (acetic acid) is classified as a weak acid.- \( \text{H}_2\text{CO}_3 \) (carbonic acid) is classified as a weak acid.- \( \text{HNO}_3 \) (nitric acid) is classified as a strong acid.Answer: Consequently, \( \text{HNO}_3 \) is identified as a strong acid. Thus, the correct option is (4).