Final answer:
The subject of the question is Spanish and the correct answer is B. Ella (She)
Step-by-step explanation:
The subject of the question is Spanish. The question is asking about the subject of the sentence 'Es muy buena profesora, señora Ruiz' (She is a very good teacher, Mrs. Ruiz).
The correct option is B. Ella (She) because it agrees with the feminine subject of the sentence, 'señora Ruiz' (Mrs. Ruiz).
Therefore, the correct answer is B. Ella (She).
Learn more about Subject in Spanish sentences