It would be "Sé Bueno" if thats what your looking for
Eres bueno = you are good
ser bueno = to be good
seas bueno , I really don't know but I it's not the answer
Answer:
the answer is D. Future tense
Explanation:
yo estaré
tu estarás
el estará
nosotros estaremos
ellos estarán
Si un estudiante quiere ir al ARMARIO, le digo que no.