51. The Nuclear Non-Proliferation Treaty came into force in - A.1967 B.1970 C.1971 D.1974
Option B Solution: Opened for signature in 1968, the Nuclear Non-Proliferation Treaty entered into force in 1970. On 11 May 1995, the Treaty was extended indefinitely. A total of 191 States have joined the Treaty, including the five nuclear-weapon States.
