Which aspect of the roman empire continued into the byzantine empire

The need for fighting off invading groups.

Explanation:

Byzantine Empire came into existence after the fall of the Roman Empire. The major contribution of the empire was to preserve the Greek language and culture as well as the Romans. The necessity to fight the enemies and stop them from invading remains the same in both Empires. Both empires built on the strong military, which helped them to rule over Europe and expand its territories. Byzantine Empire ruled most of Eastern and Southern Europe.

both believe in many god or polytheism

both built temples that they worshiped in both civilization's god were humanoid

both groups made religion a large portion of their lives

both believe in one religion throughout

the dead were buried with items for the afterlife

i think it's a)sparta