Which sentence has correct pronoun-antecedent agreement?

A. The twins laughed so hard she cried.
B. The raindrops poured down, and it drenched the yard.
C. The brother were getting along so well that he decided to go on a bike ride together.
D. Mrs. Smith was excited to teach her class

Mrs. Smith was excited to teach her class I think

In which one do they match (singular/singular or plural/plural)?

A. twins…she
B. raindrops … it
C. brothers … he (I think there's a typo in your post.)
D. Mrs. Smith … her

yea

Correct.

To identify the sentence with correct pronoun-antecedent agreement, we need to check if the pronoun and its antecedent (the word the pronoun is referring to) agree in number and gender.

A. The twins laughed so hard she cried.
Here, the antecedent is "twins" (plural), and the pronoun is "she" (singular). This sentence has incorrect pronoun-antecedent agreement.

B. The raindrops poured down, and it drenched the yard.
In this sentence, the antecedent is "raindrops" (plural), and the pronoun is "it" (singular). This sentence also has incorrect pronoun-antecedent agreement.

C. The brother were getting along so well that he decided to go on a bike ride together.
Here, the antecedent is "brother" (singular), and the pronoun is "he" (singular). This sentence has correct pronoun-antecedent agreement.

D. Mrs. Smith was excited to teach her class.
In this sentence, the antecedent is "Mrs. Smith" (singular), and the pronoun is "her" (singular). This sentence also has correct pronoun-antecedent agreement.

Therefore, the sentence with correct pronoun-antecedent agreement is D. Mrs. Smith was excited to teach her class.