Final answer:
To change the infinitive verb 'cumplir' to the affirmative form, use the correct conjugated form based on the subject, in this case, 'cumple' for 'he' or 'she'.
Step-by-step explanation:
To change the infinitive verb 'cumplir' to the affirmative form, you would use the conjugated form of the verb that matches the subject. In this case, the correct option is B. 'Cumple.' This form is used with the subject 'él' or 'ella' which means 'he' or 'she' in English.
Learn more about Conjugating verbs in Spanish