Respuesta :
Answer: Mi papá está en la escuela.
Explanation: We must complete the sentence:
"Mi papá ___ en la escuela"
That can be translated to:
"My dad ___ in the school"
Now, remenber that "ser" is used for adjetives like "mi papá es grande"
And estar is used for states or places "Mi papá está cansado" or "mi papá está en casa"
Now we have a location, the school, so we should use "está"
Mi papá está en la escuela.