What factor played in the largest role in producing the dramatic drop in the native population of the new world that followed the arrival of europeans?

The main factor was the diseases introduced by the Europeans.

Explanation: Many factors contributed to the death of Native Americans after the arrival of Europeans .

Native Americans were killed by Europeans during wars , they also turned them into slaves and treated them harshly which increased death of Native Americans.

The main factor though that resulted to a high percentage of Native Americans' deaths was the diseases brought by the Europeans.

The common disease is said to have been smallpox to which they were not resistant and when they tried to escape they infected even more numbers of other Native Americans who were not yet exposed .

a) they had recently endured the tyranny of the british king, parliament, and its royal