Answer:
C. Chemical weapons.
Explanation:
TL:DR Chemical gas is a war crime due to the amount of suffering it causes. Mustard gas burns the skin, Phosgene is impossible to see, and Chlorine can make you drown in your own body.
Machine guns had been in use and invented since 1908, with invention of weapons such as the Vickers and German Maschinegewehr 08. Trench warfare wasn't a weapon, but more of a tactic. Mines weren't a war crime either as they most likely weren't deemed to cause "unneeded suffering" and their purpose usually was to simply discourage the travel of an area. Usually, if you stepped on a mine you'd die.
Meanwhile, Chemical gas was simply invented on accident as the German Empire's scientist,
Have you ever heard about Louis and Clark and Sacagawea? Anywho after the territory was bought from France Jefferson, the president at the time, sent a group of men to explore the territory. They were led by Louis and Clark, they met an Indian tribe and an Indian woman helped them on their journey.
Answer: C) Warfare with others.
Explanation:
The earliest known people of Oklahoma were Osage, Quapaq, Caddo Witchita, Waco Tawakony, Comanche, Apache and several other tribes. When the white men started to encroach upon their land it led to constant warfare. Which was a major cause for the decline in their population. Another factor was that they were uprooted to make Oklahoma available for White men after 1865.
I would say false since I believe that it united opposing the federalist claim.