Which describes how the pronoun is used in the sentence? The first person in the door was she.

a. object of a preposition

b. subject

c. predicate nominative

d. direct object

I think the correct answer is C. The pronoun was used as the predicate nominative of the sentence. The predicate nominative is a pronoun or a noun which is next to a verb and it describes or renames the subject. It usually follows a linking verb or a verb phrase. For this case, it is followed by the verb phrase "was".