Final answer:
Improved transportation and communication systems were major effects of European rule in Africa, enhancing economic efficiencies but also leading to social disruption and increased dependence on imports.
Step-by-step explanation:
A major effect of European rule in Africa was C) improved transportation and communication systems. The colonial period led to major technological transfers from Europe to Africa, which infused greater efficiencies into Africa's economic activities. Although there were various impacts, the development of infrastructure such as railways, ports, and telegraph lines significantly improved transportation and communication across the continent. This came as part of the European powers' efforts to exploit the continent's natural resources more effectively and integrate African economies into the global market.
However, this infrastructure and economic development often came at the cost of social disruption and exploitation. Trade in slave labor and the imposition of European economic systems resulted in increased dependence of African nations on imports and a shift away from subsistence agriculture. Local industries such as cloth production were also harmed by the influx of European goods, such as textiles, which African producers could not compete with in terms of quantity or price.