Answer:
B. The Edict of Milan helped spread Christianity by allowing all religions in Rome.
D. He believed that locating the capital in an area that had more trade and business would ensure the future of the empire.
Step-by-step explanation:
The great achievement of reign of Constantine is the Edict of Milan that helped in spreading of Christianity in Rome. He was the first roman emperor which profess the religion of Christianity in the year 313. This proclamation legalized the Christianity religion and allowed all people of Rome the freedom of worship throughout the empire. Constantine move the capital of the Roman Empire because he wanted that the capital will become the economic, cultural hub and center of the east.