Emperor Constantine had accepted Christianity. So the edict of Milan helped spread Christianity by allowing all religions in Rome. so the correct option is B.
Constantine was the great emperor of the roman kingdom from 306 to 337ce. He lived most of his life as a pagan later becoming a catechumen and finally, he adopted chritianity.
Emperor Constantine had constructed many churches in the capital in the 4th century. Constantine also introduced Christmas as an immovable festival on 25 December in 325AD.
Therefore the correct option is B.
Learn more about great Constantine here:
brainly.com/question/1566829