1. The Great Plains became suitable for farming only after the development of plains technology such as:
a. mining, barbed wire, and cattle trails.
b. railroads, fertilizers, and steel plows.
c. windmills, barbed wire, and steel plows.
d. railroads, Indian reservations, and fertilizers

c. windmills, barbed wire, and steel plows.

Explanation:

Farming in the Great Plains was no always suitable for farming for a variety of reasons such as cattle coming into fields and eating crops, water shortage and soil that was very difficult to plow.

New technology like windmills, barbed wire, and steel plows helped solve these problems thus the Great Plains became suitable for farmers.

The barbed wire fences stopped cattle from coming into the fields and eating the crops which ended what was known as the "range wars".

Windmills were used to pump water from underneath the ground more effectively which solved the water problems that the Great Plains had.

And finally, steel plows were able to cultivate the tough Great Plains soil and prevent it from sticking too much which enabled seeds to be sown.

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