The Limited Test Ban Treaty (LTBT) signed in 1963 banned nuclear weapon tests:

Correct option is D

The correct answer is (d) Only in the atmosphere, outer space and under water
Explanation:
● The LTBT (Limited Test Ban Treaty) was signed by the US, UK, and USSR in Moscow in 1963.
● It prohibited nuclear explosions in the atmosphere, in outer space, and under water.
Information Booster:
● The treaty did NOT ban underground nuclear tests, as long as radioactive debris did not cross national borders.
● This was a major step toward arms control during the Cold War.
Additional Knowledge:
● The Comprehensive Nuclear-Test-Ban Treaty (CTBT) later aimed to ban all nuclear explosions, including underground ones.