In which year did the United States and Soviet Union sign the Anti-Ballistic missile Treaty(ABM)?

1972

The correct answer is Option (2) → 1972

The Anti-ballistic Missile (ABM) Treaty in 1972 tried to stop the United States and Soviet Union from using ballistic missiles as a defensive shield to launch a nuclear attack. While it did allow both countries to deploy a very limited number of defensive systems, it stopped them from large-scale production of those systems.