Which of the Following Statements About Slavery in Europe Before

Which of the following statements about slavery in Europe before 1450 was most accurate?

A) Europe had never had a tradition of slavery.
B) Slavery had been extensive in the ancient world, but had died out during the Middle Ages in all regions in the West.
C) Slavery had died out in the Middle Ages in most of Europe except along the military frontier between Christians and Muslims in the Mediterranean.
D) Slavery was common to Europe in all eras prior to 1450, although it tended to become more dominant during the Middle Ages.