Final answer:
The subject pronoun that matches the subject in the sentence "El señor Guzmán es profesor de español" is él (OC).
Step-by-step explanation:
The subject pronoun that matches the subject in the sentence "El señor Guzmán es profesor de español" is él (OC). It refers to a male singular subject, which in this case is "El señor Guzmán". The pronoun "él" is used to replace the noun in the sentence to avoid repetition.
Learn more about Subject Pronouns in Spanish