Which pronoun would correctly fill in the blank in the following sentence? I think that either my cousins or your husband will bring _____ sound system to the party.

In this sentence, the blank should be filled with "their" because it is used as a gender-neutral singular pronoun that can refer collectively to the antecedents "my cousins" or "your husband."

When we have a compound subject like "my cousins or your husband," the pronoun that follows should match the plurality of the antecedents. The term "their" appropriately encompasses both "my cousins" (plural) and "your husband" (singular), making it the most appropriate choice.

Using "his" or "her" would limit the reference to one of the singular antecedents, which would not accurately represent the statement, as it could apply to either of the subjects. "Its," being non-human in reference, would not fit the social context of cousins and a husband, as it typically pertains to objects or animals. Thus, "their" is the best fit, expressing inclusivity for both individuals in the context of the party and the sound system.