Question

cantamos una canción __ en el auditorio del centro internacional. perúano peruanas peruanos

Explanation:

In Spanish, "canción" is a feminine - singular noun. So, we need a feminine - singular adjective to modify it. "peruano" is masculine - singular, "peruanos" is masculine - plural, "peruanas" is feminine - plural, and "peruana" is feminine - singular.

Answer:

peruana