B) Patronage by the masses
Probably propaganda around the place
They were an investment and used as goods for sale. This practice was used up to the 1850's when the US banned it. But other slaves came from this which included Chinese, Italian Irish etc.
called caboclos, as well as assimilated, westernized Amerindians, and mestizos with some Asian ancestry. A majority of mixed-race Brazilians have all three ancestries: Amerindian, European, and African.