What event made the strongest impact on the growth of Walla Walla?

Hostile Natives American tribes being placed on reservation

Discovery of gold in the Idaho hills

Construction of a military road linking Walla Walla with Fort Benton

Success of growing wheat in the dry hillsides

The correct answer is D. Success of growing wheat in the dry hillsides.

Explanation:

In the 1860s, some farmers who were pioneers found out that the particular place of Walla Walla was a very special place and well-suited to cultivate or make wheat to grow. And because of this, Walla Walla grew to make a great impact on the nation.