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.
I believe your answer will be 3.
Answer:
1: Tráigame el periódico.
2: Leanle sus composiciones en voz alta.
3: Escríbale la carta esta tarde.
4: Déme los papeles ahora mismo.
5: Diganos el secreto.
6: Vendale el coche enseguida.
7: Construyan una casa original.
8: Cuénteme su chiste favorito.
Explanation:
I don't really understand what are you trying to say, but the answers are for the blank spaces.