What Historical Evidence Demonstrates That Blacks Were Being Held as Slaves

What historical evidence demonstrates that blacks were being held as slaves for life by the 1640s?

A) Property registers list white servants with the number of years they were to work, but blacks (with higher valuations) had no terms of service associated with their names.
B) Transcripts from legislative debates in the House of Burgesses show that Virginia lawmakers were debating whether permanent slave status was a good idea.
C) Records of declining tobacco prices show that it had become harder to keep labor, which would have forced planters to turn increasingly to Africans and away from white servants.
D) There is none, because slavery did not fully exist in Virginia until after Bacon's Rebellion in 1676.
E) Advertisements for slaves began appearing in newspapers regularly by 1642.