the answer is A. Imperfecto progresivo.
The progressive imperfect is used to express something that was taking place in the past. It is formed using the verb to be in past (in this case: estaba) plus the verb ending in ing (ando, endo, in this case: cantando). It is mainly used for: on-going actions that were happening in the past.
A DONDE vamos cuando queremos comer? where do we go when we want to eat?
Answer:
La palabra que ayuda al lector a entender lo qué significa artefacto es "Avión"
Porque artefacto es un objeto formado por un conjunto de piezas y fabricado para un fin determinado, en especial el que no constituye una máquina, aparato o dispositivo definidos.
i believe it should be "add the new ending to the infinitive" and "don't drop the -ar, -er, and -ir"
