The Russian Revolution was sparked by the manner in which the people were treated and the miserable conditions in which they were living under the Tsar Nicholas II. The people were not willing to put up anymore with the poverty and unjustly treatment towards them, so led by Vladimir Lenin, they revolted. The revolution was successful at the end, and it put end to the monarchy in Russia, while it opened up the doors for the communism at the same time. Unfortunately for the Russians, the century ahead of them didn't turned out to be better, but the same, or even worse at times.
C and d have to do with the upper classes and how they (mostly) utilized labor. Populists were more concerned with how to make things work for them (a bit cynical on my part).
The progressives (particularly women and labor leaders) were very concerned about working conditions and how to improve them.
B<<<< answer
<span>a plan for states’ representation in Congress
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