The correct answer is option B) The slave trade had weakened many African Kingdoms.
The Europeans were able to conquer large parts of Africa. This gave them access to not only natural resources but also human resources.
The Africans were quickly enslaved and were exported and sold throughout the world to work in plantations and other labor intensive jobs.
The discovering of the New World also provided these Europeans with a large market to sell these slaves.
African slaves were shipped off to both South America and North America. Millions of African slaves were sold off, with many thousands of them dying on the way.
The huge trade provided Europeans with large sums of money and even free labor to work on their mines and plantations.
In all this, many African Kingdoms deteriorated due to a loss in population. The Europeans began to carry out raids on African town and villages to capture people. This turned into a cyclic problem, where African kingdoms lost men and in turn could not defend themselves.