I’m so happy that you have
Beowulf went to battle because Grendel attacked a nearby village and the king of that village asked Beowulf for help.
Antecedent is an expression that gives meaning to the word coming after that. For example, I was late to the meeting because police held me for speeding. In this sentence, pronoun me is an explained word which explain another pronoun - I. Antecedent has been used correctly in this sentence. In this question, the first option is correct. Antecedent has been used incorrectly in the second sentence because it's unclear who is considered with the pronoun he. The third option is also an incorrect antecedent because the explaining word has not been given.
