The Nuclear Non Proliferation Treaty of 1968 was an _____.

Arms control treaty

The correct answer is Option 1 - Arms control treaty

Various Arms control treaties:

LIMITED TEST BAN TREATY (LTBT)
NUCLEAR NON-PROLIFERATION TREATY (NPT)
STRATEGIC ARMS LIMITATION TALKS I (SALT-I)
STRATEGIC ARMS LIMITATION TALKS II (SALT-II)
STRATEGIC ARMS REDUCTION TREATY I (START-I)
STRATEGIC ARMS REDUCTION TREATY II (START-II)

NUCLEAR NON-PROLIFERATION TREATY (NPT): Allows only the nuclear weapon states to have nuclear weapons and stops others from acquiring them. For the purposes of the NPT, a nuclear weapon state is one which has manufactured and exploded a nuclear weapon or other nuclear explosive device prior to 1 January 1967. So there are five nuclear weapon states: US, USSR (later Russia), Britain, France and China. Signed in Washington, London, and Moscow on 1 July 1968. Entered into force on 5 March 1970. Extended indefinitely in 1995.