Answer :
The original purpose of the Selective Service Act of 1917 was to draft Americans into the armed forces. This was used as a means to increase the size of the American army during World War I.
The answer is 3: To draft Americans into the armed forces.
Selective Service Act of May 18, 1917, was a U.S. federal law that allowed the government to draft Americans into the armed forces for their entry into World War I on April since at the time, the U.S. Army wasn't numerous enough. All male Americans aged 21 to 30 were required to register to be selected for military service. On August, the law expanded the age range from 18 to 45.