Final answer:
Iron tools substantially increased agricultural productivity and played a role in military conquests in the Kingdom of Ghana.
Step-by-step explanation:
The introduction of iron tools had a significant impact on the Kingdom of Ghana, which was settled around the confluence of the Benue and Niger Rivers in present-day Nigeria. The use of iron technology allowed for an increase in agricultural productivity by facilitating the clearing of forests and the establishment of trench-based irrigation systems, thereby improving the efficiency of farming.
Moreover, iron tools and weapons provided the means to conquer neighboring territories, facilitating the expansion and consolidation of kingdoms. These advancements were not just for utilitarian purposes but also propelled social changes, sparking the rise of a more powerful merchant class and stimulating long-distance trade.
The Kingdom of Ghana utilized iron tools for both agricultural improvement and military conquest, rejecting the option that they were used solely for artistic purposes or had no impact at all.