Final answer:
The sentence, "The referees made their rescuing about the final play," is written in the possessive case.
Step-by-step explanation:
The sentence, "The referees made their rescuing about the final play," contains a possessive pronoun. The possessive pronoun in this sentence is 'their.' Possessive pronouns show ownership, and in this case, 'their' refers to the referees. Therefore, the sentence is written in the possessive case.