Answer:
A menudo compartíamos con mi hermana.
Step-by-step explanation:
A menudo compartíamos con mi hermana. This means: We usted to share things with my sister often. The verb "compartíamos" is in the imperfect, it means the sentence is referring to something in the past. All the other three options are referring to the future: A) In dos días más means "in two days". B) Mañana por la mañana, means "tomorrow morning". And D) El próximo mes, means "next month". So neither of them could be used to talk about the future.