The correct answer is B. Disease spread through American Indian communities.
Step-by-step explanation:
One of the main effects or consequences of the Europeans arrival to the Americas was the spread of diseases in natives and the death of many Indians as a result of these. Indeed, European colonizers took with them to America some diseases including smallpox or cholera and these resulted to be lethal for Indians because never before they had had contact with these diseases, and therefore they did not have an appropriate immune response. This reduced significantly many Indian tribes and even contributed to the disappearance of small tribes.