The pronoun used in both 16a and 16b is a reflexive pronoun. In this case, the pronoun "it" refers back to the game that is being requested. By using a reflexive pronoun, the sentence avoids repeating "the game" again and again. In 16a, "it" is used as a gender-neutral pronoun, while in 16b, "his or her" is used to show inclusivity towards both genders.