Answer:
I'm not sure, but either B or D
Explanation:
The Christian church could have survived without the Roman Empire, but it helped boost its popularity. D. Because it was one of the first Democraticish types of government that are still used today.
Old Major is the allegorical figure for Karl Marx or Vladimir Lenin, depending on your interpretation of the text. Both men stood for basically the same thing, and these things was what Orwell was exploring in the novel.