What does ca. mean in history?

Question 4 of 10 2 points how were the reasons for a person's enslavement different in west african cultures than in the atlantic slave trade? o a. in west african cultures, any unmarried man could be enslaved, while in the atlantic slave trade, only prisoners of war could become slaves. o b. in west african cultures, people had to be born into slavery, while in the atlantic slave trade, people had to commit a crime to become a slave. o c. in west african cultures, people could only become slaves if they owed debts, while in the atlantic slave trade, slavery was used to punish crimes. o d. in west african cultures, people were enslaved through war or as punishment, while in the atlantic slave trade, anyone could be ſom captured and enslaved previous obi