What was the impact of copper on the town of Kennicott?

The correct choice highlights the significant impact that the depletion of copper resources had on the town of Kennicott. As a mining town, Kennicott thrived during the period when copper was being actively extracted. However, once the copper resources were exhausted, the economic foundation of the town collapsed, leading to its abandonment. This illustrates the typical cycle of resource-based settlements, where the prosperity is typically directly tied to the availability of the resource being mined. In the case of Kennicott, after the copper ran out, there were no longer sufficient reasons for people to remain, resulting in the eventual decline and desertion of the town.