Which of the technological developments gave European armies an advantage over African armies?

The technological development that gave European armies a significant advantage over African armies is primarily A. Repeating Rifle. The repeating rifle allowed soldiers to fire multiple rounds without reloading, greatly increasing their firepower and effectiveness in combat.

While the electric telegraph, Bessemer Process, and steam engine also had important impacts on warfare and logistics, the repeating rifle is the most direct factor that improved the effectiveness of European military forces in confrontations with African armies during the colonial period.