Final answer:
The appropriate verb to fill in the blank is 'tienes.' In Spanish, 'tienes' means 'you have' and is used to ask someone's age.
Step-by-step explanation:
The appropriate verb to fill in the blank in the sentence is A. tienes.
In this sentence, the subject is 'tú' which means 'you' in English. The verb 'tienes' means 'you have' and is used to ask someone's age in Spanish.
For example: ¿Cuántos años tienes tú? - How old are you?
Learn more about Spanish verbs