Answer:
New railroads and refrigerated cars.
Growing cities in the East.
Barbed-wire fences.
Step-by-step explanation:
These were all developments that helped make the cattle business profitable. New railroads and refrigerated cars made it easy to transport cattle over long distances. Moreover, the growing cities in the East increased demand for cattle. Finally, barbed-wire fences allowed farmers to have better control over their animals and their territory.