Which geographic features helped sustain West African trade?

The region of West Africa includes the southern portion of the bulge of the continent, which extends westward to the Atlantic Ocean. This region is bisected by the African Transition Zone, which borders the southern edge of the Sahara Desert. The main physical features include the Sahara Desert and the Niger River.

4 copper and gold, the california gold rush is why im pretty sure.

answer: the correct answer is d. a christian revivalist movement in the u.s. during the early 19th century

explanation: the second great awakening was lead by the preachers of baptist and methodist congregations in order to gain support for the protestant religion from the 1790's to 1840's