Final answer:
The element characteristic of slavery in West Africa prior to the Atlantic slave trade was that enslaved people often became part of the extended tribal group, were not always enslaved permanently, and children of slaves could be born free.
Step-by-step explanation:
The characteristic element of slavery in West Africa prior to the Atlantic slave trade that is most accurate is that enslaved people often became part of the extended tribal group. Unlike the chattel enslavement that became common during the transatlantic slave trade, where enslaved people were treated as personal property without any rights, West African slavery allowed for some integration into society. Enslavement in this context was not necessarily a permanent condition, and children born to enslaved people were often free. Also, the enslavement of individuals was often a result of war, debts, or political instability.
Slavery in Africa has a long history and existed in various forms. Before the European engagement in the transatlantic slave trade, African societies captured and enslaved people through warfare, exerted control over them, but did not always treat them as chattel. These enslaved individuals could eventually assimilate into the capturing society. Furthermore, in some cases, slaves could gain their freedom or were not enslaved for life, a stark contrast to the harsh conditions of the chattel slavery system that developed in the Americas, driven by the transatlantic slave trade.