Final answer:
Tanzania, Somalia, Kenya, Mali, Sierra Leone, and Algiers are all located in Africa, which is option C) Africa on the list. The region of Africa most involved in the Trans-Atlantic slave trade was West Africa.
Step-by-step explanation:
Tanzania, Somalia, Kenya, and Mali, Sierra Leone, and Algiers (which is the capital city of Algeria) are all located in Africa. This places the correct answer to the student's question as option C) Africa.
These countries and Algeria are distributed across different regions of the African continent, with Tanzania, Somalia, and Kenya in Eastern Africa, Mali and Sierra Leone in West Africa, and Algiers in North Africa.
Regarding the history of Africa, the region most directly involved in the Trans-Atlantic slave trade was West Africa. This is important to note as it reflects the historical significance of some of the regions mentioned in the original question.
Eastern Africa, particularly along the Swahili coast, was also known for the trade of enslaved people sourced from the interior of the African continent. The correct option is c.