Answer :
The correct answer is B) financial gains.
These slavers were primarily interested in financial gains.
It was so simple, slavers were interested in money, in financial gains. Slavery was a great business for slavers who saw slaves not as a human, but as a property that had some value and could be sold. Slaves were like any product to be traded such as sugar, or cotton, or salt. That was inhuman but was a very profitable business for so many people for so many time.