I think it's "Tú eras bajo." because "eres" is present and I'm pretty sure "eras" is the past tense of ser!
Answer:
Juan cumple 16. este año
Explanation:
It just sounds better than the rest of the phrases,
Revisa este link si habla que habla de las comunicaciones. Verbal No Verbal etc https://economipedia.com/definiciones/tipos-de-comunicacion.html
