Answer:
It led the UFW to focus on issues that affected American Indians.
Explanation:
I believe that the Sioux were most impacted by the Transcontinental railroads. The building of the railroads impacted the Great Plains tribes, and among your options, only the Sioux were situated there, whereas Pueblos and Navajos were elsewhere.
The reasons why they were most impacted are numerous. First of all, when the railroads were built, they passed through the Native American lands, which were protected by the American government which obviously went back on their word. Additionally, when the railroads were made, it affected the flora and fauna in the Great Plains, and many animals (especially the bison) were almost extinct which affected the Sioux, who were a hunting tribe.
The U.S. entered World War I because Germany embarked on a deadly gamble. Germany sank many American merchant ships around the British Isles which prompted the American entry into the war
Blacklisting of many people in the entertainment industry is the answer
