Pronoun-antecedent agreement

13a. Most presenters spoke without looking at his or her notes.

13b. Most presenters spoke without looking at their notes.

My answer is: 13b

Again, I believe this to be correct.

Right.

Correct! The correct answer is 13b: "Most presenters spoke without looking at their notes." This is an example of pronoun-antecedent agreement.

In a sentence, a pronoun should agree in number (singular or plural) with its antecedent (the word that the pronoun refers to). In this case, the antecedent is "presenters," which is plural. Therefore, the pronoun should also be plural.

In 13a, the pronoun "his or her" is singular and does not agree in number with the plural antecedent "presenters." On the other hand, in 13b, the pronoun "their" is plural and matches the plural antecedent "presenters." Hence, 13b is the correct option for pronoun-antecedent agreement.