Find out the correct pronouns from the bracket.
__________ is my sister.

The correct answer is: She

The correct answer is "she".
From the above-mentioned example, we can say that the speaker is talking about his sister. Here, the subject is used as the substitute of his sister, and to represent it, we must use a third person singular number pronoun. Among the given options, the words "he", "it" and "she" have a similar feature, but since the speaker's sister is a girl, a feminine gender pronoun must be used. So, the correct answer is "she".