In its discussion of external evidence, the passage suggests which of the following about manuscripts of ancient Roman texts during the Middle Ages? A. It is possible that fewer manuscripts were destroyed by barbarians in the early Middle Ages than scholars frequently suppose. B. Additional copies of some so-called lone survivor manuscripts may have existed well into the Middle Ages. C. If an ancient Roman text is quoted in a work by a medieval author, then it is likely that at least one manuscript copy of that text survived into the Middle Ages.