What migration pattern occurred because of the belief that the Great Plains was too dry for farming?

A. Fur traders migrated to the South from the northeast.

B. Settlers who wanted to farm migrated west to Oregon Country.

C. Spanish settlers decided to lay claim to the more fertile Oregon Country.

D. Settlers migrated to the Great Plains from the southern and eastern regions.

This event happened:

B. Settlers who wanted to farm migrated west to Oregon Country.

Explanation:

The Great Plains had been too dry to farm due to the climate that they offered as they could not support the extensive farming and had only been suitable for grass.

The settlers who had wanted to farm thus had to move away to lands they could use to farm.

The lands that they had picked thus were in Oregon county which became one of the most fertile regions of the whole area and was the bread basket of the region.

i believe the answer is d.