The correct answer is A) Cattlemen let their cattle roam onto the farms, trampling crops.
Farmers started building barbed wire fences on their farms in the Great Plains because cattlemen let their cattle roam onto the farms, trampling crops.
And these actions generated many problems. Framers spend so much time working long hours under the sun producing quality cash crops. They invested time, effort, and money to have good crops. Then cattlemen did not pay attention to where the cattle roamed. Cattle of course trambled everywhere and destroyed crops and ate crops, plants, and the grass on private property.
Farmers used barbed wires to protect their private property and avoid major conflicts.