Our friends, . . . . . . . . we invited to party, arrived rather early. A. which B. whom C. whose D. who

The correct answer is D. who.

The pronoun “who” is used to refer to people. In this sentence, “who” is the subject of the verb “arrived.” The sentence could be rewritten as “Our friends, who we invited to the party, arrived rather early.”

The pronoun “which” is used to refer to things. In this sentence, “which” would not make sense because “friends” are people, not things.

The pronoun “whom” is used to refer to people as the object of a verb or preposition. In this sentence, “whom” would not make sense because “friends” are the subject of the verb “arrived.”

The pronoun “whose” is used to show possession. In this sentence, “whose” would not make sense because “friends” are not possessive.