Respuesta :
The correct answer is
B.) through the draft authorized by the S.S.A
:)
The U.S. Army recruited most of the 4 million U.S. servicemen who served during World War I through the draft authorized by the Selective Service Act of 1917. Although its constitutionality was unclear at the time of its enactment, the Supreme Court upheld its constitutionality the next year, in 1918.