Reaper and steel plow were the machines invented by Cyrus McCormick and John Deere that made large-scale agriculture possible, especially on Midwestern prairies.
B) Reaper and steel plow
Step-by-step explanation:
In the 1800's people used to do all the chores with their hands hence, it made farming a tough job and a lot of time consuming activity. During the industrial revolution, Cyrus McCormick invented a mechanical reaper, which would help reap big farms in very less time.
The steel plow played a very important role in the industrial revolution as the wooden plow used to be weak but John Deere's invented steel plow was strong and broke soil easily.