By 1575, the Spanish and Portuguese Brought More Than 120,000

By 1575, the Spanish and Portuguese brought more than 120,000 enslaved Africans to their American empires because:

A) they wanted to assimilate their culture with that of the Africans.
B) of the restrictions set by royal authorities on the exploitation of the Indian population.
C) they wanted to replace their native labor, which faced depopulation due to conquest and disease with African slaves.
D) of the threat of revolt from the Indian population.