Which of the following sentences demonstrates correct subject-verb agreement?

The sentence that demonstrates correct subject-verb agreement is structured around the collective noun "committee." In English, collective nouns can be somewhat tricky, as their usage can vary based on whether the group is being considered as a single entity or as individual members. In this case, "The committee... votes" treats the committee as a single unit making a decision, which is why the singular verb "votes" is appropriate. This maintains agreement between the singular subject "committee" and the singular verb "votes."

In contrast, the other sentences fail to utilize the correct subject-verb agreement because they treat collective nouns or subjects in a way that implies plural action or decisions. For example, "The group of children are ecstatic" incorrectly uses the plural verb "are" when "group" should take a singular verb form. Similarly, "The family... agree" and "The couple decide" have plural verbs paired with singular collective nouns, which disrupts the subject-verb agreement required in standard English usage.