Concept:The Oyo Empire reached its greatest power and stability during the reign of the Alaafin who restored peace after internal conflict.
Explanation:Alaafin Abiodun ruled the Oyo Empire in the late eighteenth century.
He came to power after overthrowing the powerful Bashorun Gaha, ending a period of political crisis.
Under Abiodun, the empire enjoyed peace, unity, and economic prosperity.
His leadership strengthened Oyo's military and extended its influence over neighboring states.
Trading activities also increased, especially through the coastal port of Porto-Novo.
This made his reign the period of greatest stability and territorial reach.
Historians therefore describe his rule as the peak of the Oyo Empire.
Answer:D. Abiodun