Question

¿Adónde vamos cuando necesitamos comprar medicina? Vamos a la farmacia. Vamos al teatro. Vamos a la fábrica. Vamos a la avenida.

Answer 1

The answer is "vamos a la farmacia" because it means we go to the pharmacy.

Answer 2

¿Adónde vamos cuando necesitamos comprar medicina? 

Translation:
Where do we go when we need to buy medicine?

The options:
Vamos a la farmacia. - "We go to the pharmacy."
Vamos al teatro. - "We go to the theatre."
Vamos a la fábrica. - "We go to the factory."
Vamos a la avenida. - "We go to the avenue."

You don't go to any of the last three places if you're looking to buy medicine.

Answer:
Vamos a la farmacia.