Prior to the presence of europeans on the continent, the slave trade in africa
a) did not exist in any form.
b) was limited to internal trade only.
c) included the trans-saharan and indian ocean slave trade.
d) was rarely needed due to the lack of an agricultural economy.

The right answer is B.

Explanation:

Before the arrival of the Europeans, African kingdoms or other political units had their own forms of slavery. People became slaves as punishment for a crime, as payment for a debt, or being captured as a prisoner of war. Those are patterns seen in other civilizations as well. Despite the existence of those forms of slavery, it can´t be compared with what was done by the European slave traders.

Prior to the presence of Europeans, the slave trade in Africa took place both internally and along the great Indian Ocean.

Option C.

Explanation:

The slave trade along this Trans Saharan and Indian Ocean Region dates back to 8th century. Most of the slaves were traded in Arab for the purpose of household duty, though were subjected to all forms of torture about which, all of us know.

The slave trade also was common internally in the Africa where military soldiers of the defeated army and weak clan members were captured and made slaves.

it's not the readmission

the exclusive possession or control of the supply or trade in a commodity or service.