About 100 years ago, of people lived on farms in rural areas.
a. 20 percent
b. 80 percent
c. 60 percent
d. 50 percent

I am pretty sure that about 100 years ago, 60 percent  of people lived on farms in rural areas. I consider this option as the most suitable one as in this perion of time in most of rural areas there was quite  nice conditions for setting a farm and growing plants in there. It was good both for life and for bussiness, so a lot of people support the idea of living on farms.
Do hope that helps!

The best sentence that summarizes the quotation “The fruits of the toil of millions are boldly stolen to build up colossal fortunes for a few, unprecedented in the history of mankind; and the possessors of those, in turn, despise the republic and endanger liberty. From the same prolific womb of governmental injustice we breed the two great classes—tramps and millionaires.”  is the wealthy often profit from the hard work of the lower class. The quotation tells us about injustice, oppression and poverty.