The early settlers faced numerous challenges while living in the harsh environment of the Plains. Out of the options provided, the most fitting would be:
B) They made good use of raw materials.
Settlers adapted to their environment by utilizing available resources for shelter, fuel, and food. They built homes from materials like sod, which was readily available, and relied on resources like buffalo and crops for sustenance. While partnerships with Plains Indians (option A) did exist, they were not the primary means of survival. Option C, "they planted acres of trees," was not common on the Plains due to the limited availability of water and the challenging growing conditions.