Final answer:
The correct chronological order is the Edict of Milan, the split of the Roman Empire, the establishment of the Eastern Orthodox Church, and the formulation of the Nicene Creed (option a). These events highlight the significant transformations in religious and imperial structures during the Roman Empire's history.
Step-by-step explanation:
The correct chronological order of the events listed in the choices provided is: Edict of Milan, Roman Empire is split, Eastern Orthodox Church established, Nicene Creed. These events reflect significant moments in the transformation of the Roman Empire and the rise of Christianity as a dominant religion in Europe.
The Edict of Milan was issued in 313, legalizing Christianity.
The Roman Empire was split into the Western and Eastern Empires later that century, with increasing divergence in their governments.
The Eastern Orthodox Church was officially established after the East-West Schism in 1054, though its distinct identity had been forming for centuries as the Eastern Roman or Byzantine Empire developed separate from the West.
The Nicene Creed, a statement of Christian faith, was formulated at the First Council of Nicaea in 325.
Therefore, the answer is the sequence provided in option (a).