Which treaty limited atmospheric nuclear testing?

• A. First Strategic Arms Limitation Treaty
• B. START
• C. Non-Proliferation Treaty
• D. Partial Test Ban Treaty

Answer: (D)

This question asks which treaty limited atmospheric nuclear testing. The Partial Test Ban Treaty, signed in 1963 by the United States, the Soviet Union, and the United Kingdom, banned nuclear explosions in the atmosphere, outer space, and underwater. By removing most atmospheric tests, it reduced radioactive fallout and helped ease public fears, while underground tests could continue under the agreement.

The other options focus on limiting weapons numbers or preventing spread, rather than restricting where testing could occur. For example, treaties about strategic arms ceilings or reductions target inventories and deployment, and the Non-Proliferation Treaty aims to stop the spread of nuclear weapons rather than limit testing environments. So the Partial Test Ban Treaty is the one that specifically restricted atmospheric testing.