Answer:
Option A.
Step-by-step explanation:
white settlers discovered gold and silver in land already set aside for native Americans , is the right answer.
In the 1850's, the White Settlers in America introduced a new reservation system for the Native Americans, this system is known as the Indian reservation system. With the introduction of this system, the White Settlers could live on the lands of the Native Americans. The main reason for establishing such a system was that the White Settlers found gold in the areas inhabited by the Native American population.