Final answer:
The correct answer is 'juego'.
Step-by-step explanation:
To fill in the blank in the sentence '¡Tú __________________ muy bien al fútbol!', the correct answer is OB. juego. 'Juego' is the first-person present tense form of the verb 'jugar' (to play), which matches the subject 'Tú' (You) in the sentence.
Learn more about Verb conjugation in Spanish