A civilization is considered to be a civilization when it has an established army and has created cities, so C and E. However, this is debatable. Why this is debatable is because all of the others can be argued for. But in my opinion they are not necessary. Many civilizations lacked good governmental leaders and were run by weak leaders (for a short time though), neither are extra food supplies necessary (a civilization can raid other civilizations and steal their food supplies) nor is an education system (they can borrow educated people from other civilizations). So I would argue that one needs only created cities where people of a civilization live and a standing army.
