Final answer:
Salt was a highly prized commodity in sub-Saharan Africa due to its necessity for human health, scarceness in the region, and its use for food preservation.
Step-by-step explanation:
Salt was a valuable commodity in sub-Saharan Africa primarily because it was necessary and scarce in the region. People required salt for their health, as it helped maintain bodily functions and replenish what was lost through sweat. Beyond its dietary importance, salt also played a vital role in food preservation in the age before refrigeration. Mining sites like Taghaza provided slabs of salt that were transported by caravan across the Sahara. The king of Ghana notably valued salt highly, storing it in the royal treasury alongside gold, highlighting its worth
. The value of salt was so recognized that it was used as a form of currency in the trade across and beyond the Sahara. The establishment of trade routes and the demand for commodities such as salt helped shape the economic and political landscapes of ancient African civilizations, including the powerful Mali Empire.