The most accurate response regarding the impact of European exploration on Native Americans is:
It resulted in massive numbers of Native American deaths from new diseases.
European exploration introduced a variety of diseases, such as smallpox, influenza, and measles, to which Native Americans had no immunity, resulting in catastrophic population declines. While the other statements touch on aspects of the interactions between Native Americans and Europeans, they do not capture the profound and devastating impact of disease as a result of European exploration.