Gorbachev's Policy and the Cold War

The Cold War, a period of tension between the United States and the Soviet Union, came to an end in the late 1980s. This transformation was influenced by various factors, including internal reforms in the Soviet Union, changing political dynamics in Eastern Europe, and a shift in U.S. foreign policy. Among the key players, the policies of U.S. President Ronald Reagan and Soviet leader Mikhail Gorbachev were particularly significant.

Which of the following policies implemented by Mikhail Gorbachev was most directly associated with the reduction of Cold War tensions?