Final answer:
A) Archaeologists believe that the major cause of Native American death was the introduction of European diseases and the lack of immunity among the indigenous populations.
Step-by-step explanation:
A) Archaeologists believe that the major cause of Native American death was the introduction of European diseases and the lack of immunity among the indigenous populations.
Smallpox, diphtheria, and measles flourished among Native American tribes who had no exposure to these diseases and were unable to fight them.
As a result, these diseases decimated the tribes.
While there is some debate over whether the spread of disease was intentional or accidental, there is evidence of deliberate efforts to infect Native Americans, such as the distribution of smallpox-infected blankets as 'gifts'.