What was Constantine's primary motivation in moving the capital to Byzantium?

AIt was a strategic site which linked the western empire with the increasingly wealthy east

BIt made it easier to protect the vast empire with a more centralized capital city

CHe wanted to build a new city to honor the Christian God, as he had just converted to Christianity

DThe city of Rome had been sacked by the Visigoths and it was too expensive to rebuild on that site