Answer: its son beacuse es woudnt make sense in that sentence
Explanation: think about it quienes it wouldnt go with es bc the end of quienes is es. It would only make sense with son. its kinda hard to explain. ig since im hispanic and ive hurd and used that word before. I cant really explain it that well sory but i hope this somewhat helped but trust mi its son .
Tú eres de Peru.
Ella es mi amiga.
Nosotros somos chicos.
Él es de chile.
Yo soy inteligente.
First part is just the 2nd word if there an s at the end remove it
