Why did diocletian divide the roman empire into eastern and western sections in 285 a. d.? a) there were religious differences between people living in the eastern and western parts of the empire. b) people in the west spoke latin, while people in the east spoke greek. c) civil wars and foreign invasions showed that the empire had become too large to be ruled by one person. d) rome's conquest of the huge persian empire in the east made such a division necessary.