The options were not provided, so a general answer to the question will be provided. If Rashon wants to find out about how World War 1 affected the United States he has to make research and possibly interview people who witnessed the events. These are the primary sources.
World War 1 was fought between 1914 to 1918. Most of the people who witnessed this war might now be dead.
For Rashon to find out the most information about how the United States was affected by the first world war, he needs to conduct research from online and library sources.
He could retrieve written first-person accounts that show the personal experiences of citizens and the nation.
