The underground testing of nuclear weapons was prohibited under the terms of the 1963 nuclear test ban treaty.
a. true
b. false

Well, technically, this is false. The Test Ban Treaty of 1963 prohibited nuclear weapons testing in the atmosphere, in outer space, and under water, but it didn't ban testing underground. However, it does prohibit nuclear explosions underground if they cause "radioactive debris" and contaminate the living surroundings.