Answer:
Correct answer is They needed workers who were resistant to disease.
Step-by-step explanation:
First option is not correct as colonization of Africa started much later, and was not a part of this process.
Second option is not correct as question of slavery was not connected to church affairs.
Third option is correct as they needed workers to work on plantation, while in the same time many Natives died from smallpox and similar diseases, which led them to search for new labor force in Africa.
Fourth option is totally wrong as colonization of America was totally against the rights of Natives.