Final answer:
The true statement about the West African slave trade is that European merchants conducted trade primarily from their ships or fortified port cities, purchasing slaves from African merchants and elites.
Therefore the correct answer is option B. european merchants waited on board their ships or in fortified port cities to purchase slaves from african merchants and elites
Step-by-step explanation:
The statement that is true of the West African slave trade is: European merchants waited on board their ships or in fortified port cities to purchase slaves from African merchants and elites. This was because Europeans did not possess immunities to the diseases of the region and because they were vastly outnumbered by Africans who controlled the interior trade networks.
Instead, they relied on African political and economic elites for the capturing, transporting, and selling of slaves to European traders on the coast. African rulers varied in their approach to the slave trade, with some opposing it while others participated actively for economic gain. The slave trade required a state of warfare and had profound impacts on society by militarizing states and shifting trade orientations.