Which statement is an example of the positive aspects of the Cold War?

a. It forced Americans to confront their own racist laws and practices.

b. Superpower competition was not just about nuclear weapons; both powers competed to beat the other side to scientific and technological breakthroughs.

c. The U.S. and the Soviet Union criticized each other's violations of human rights, which promoted human rights as an important international issue.

d. All of the answers are correct.