With Regard to Disease and European Contact

With regard to disease and European contact,

A) In the Americas, the indigenous people were devastated by disease, whereas in Africa, the Europeans were not affected.
B) In the Americas, the Europeans were devastated by disease, but the indigenous people were not affected.
C) In the Americas and in Africa, indigenous peoples were affected by European diseases.
D) In Africa, disease was the major factor that enabled European conquest.