Answer: Option (4) is the correct answer.
Explanation:
Substance which are able to conduct electricity are ionic in nature. This means that only ionic substances can conduct electricity because they dissociate into ions.
Therefore, out of the given options only acetic acid [tex](CH_{3}COOH)[/tex] is ionic in nature.
[tex]CH_{3}COOH \rightleftharpoons CH_{3}COO^{-} + H^{+}[/tex]
Though [tex]CH_{3}COOH[/tex] is a weak acid but it does dissociate into ions and hence, it forms a solution that conducts an electric current.
