Which of the Following Is True

Which of the following is true?

A) The U.S. government has had ethical guidelines for medical research in place since the end of the Civil War.
B) The U.S. government did not have an official stance of what constitutes legitimate research until the mid-1960s.
C) The U.S. government did not establish regulations for scientific research until the 2000s.
D) The U.S. government began to regulate research in the 1920s prior to World War II.