Between 1870-1910, quantitative evidence shows very little, if any growth in bushels produced per acre for crops like corn and wheat. Which of the following statements correctly depicts the situation of farmers during this period?

a. Although output per acre was not growing, increased labor productivity allowed farmers to earn profits.
b. Farmers exited corn and wheat production due to lack of profits in these crops.
c. Because output per acre was not growing, farmers were forced to produce corn and wheat on farms of 60 acres or less.
d. Corn and wheat production became concentrated in the Great Lakes region, where small farms were common after the Civil War.

a. Although output per acre was not growing, increased labor productivity allowed farmers to earn profits.