What is the proper subjective case used in this context: She and ___ went to the party?

The correct answer is "he" because in the context of the sentence, "She and he went to the party," both pronouns function as subjects of the verb "went." In English grammar, the subjective case is used for subjects of verbs. "He" is the subjective case form of the pronoun referring to a male individual, and therefore appropriately completes the sentence structure.

Using any of the other options would be incorrect in this context. "Him" is the objective case and would be used if the pronoun were receiving an action, such as in "I saw him." "Them" is also objective and refers to multiple individuals, so it does not fit the singular nature of the pronoun "she." "Us" is the objective case for the first-person plural and likewise does not serve as a subject in this instance.