Which statement explains how the launch of Sputnik affected the Cold War arms race?

It convinced military leaders in the United States to begin developing an anti-ballistic missile defense shield.
It showed U.S. and Soviet leaders that conventional weapons were outdated, which led to a cut in defense spending in both nations.
It led to the development of long-range rockets that would enable the United States and the Soviet Union to attack each other directly.
It showed both superpowers how dangerous atomic weapons were, which prompted the signing of the Strategic Arms Limitation Treaty (SALT).