Which 1963 treaty prohibited nuclear explosions in the atmosphere, outer space, and underwater?

• A. The Partial Nuclear Test Treaty
• B. The Limited Nuclear Test Ban Treaty
• C. The Outer Space Arms Treaty
• D. The Anti-ballistic Missile Treaty

Answer: (B)

The idea being tested is how nuclear testing was limited to reduce environmental fallout and de-escalate the arms race. In 1963, the major nuclear powers agreed to ban nuclear explosions in three environments—the atmosphere, outer space, and underwater—while allowing underground tests to continue. This treaty directly targets the scenarios listed in the question, making it the right choice because it sets those exact restrictions on where explosions can occur, helping cut down radioactive fallout and ease international tensions.

Other options don’t fit the scenario: one treaty focuses on weapons in space rather than testing locations, and another deals with missile defenses rather than test explosions. The remaining name refers to the same 1963 agreement, though different sources may use different labels for it.