The correct answer is D. The uncovering of a land bridge that connected the two continents.
Explanation:
In general, scientific evidence and studies show the first people that settled in the American continent were Asian migrants. Moreover, the first migrations from other continents to America occurred around 14000 years ago through the Bering Strait, which is a natural land bridge that connects Asia to America.
Also, by the time the first migrations occurred this land bridge was exposed due to low-level oceans, which allowed people from Asia to migrate to the Americas by walking as they follow animal herds. According to this, the event that made possible the migration from Asia to America was the uncovering of the land bridge that connects the two continents (option D).
