Final answer:
The pronoun 'they' in the sentence provided is correctly used in the subjective case to match its function as the subject of the clause. There is no need for correction.
Step-by-step explanation:
The question asks whether the pronoun in the sentence "The surprise party was organized by Jeanette and Kirk, and it was they who diverted me from the apartment until all the guests had taken their hiding places." should be corrected. In this case, the pronoun "they" is correct since it is used as the subject of the clause following "it was." This usage conforms to the rules of pronoun-antecedent agreement and the subjective case in compound structures. When referring to subjects in a compound structure, subjective case pronouns such as 'I', 'we', 'he', 'she', 'it', 'they', and 'who' should be used. As in the examples provided, "Antonio and I have occasional disagreements about the dishes" and "It is I who arranged the meeting", 'I' and 'they' perform the action and thus require the subjective case.