I believe it's Communists.
Hope this helps!
Answer:
The rough terrain blocked its extension into eastern lands. The seas kept it from connecting with northern lands. The river systems blocked passage along the trade routes. The <u>mountains forced it to follow a central route.</u>
The assassin of President Garfield was a disgruntled office seeker. Arthur believed the Pendleton Act's merit system would prevent similar retaliations by unqualified spoils system applicants.
Droughts and severe winters were the main problems facing western cattle barons
Answer: I would say the answer is D) the study of how people use resources
