Arrange the following in a chronological order:

A. STRATEGIC ARM REDUCTION TREATY II (START II)
B. NUCLEAR NON-PROLIFERATION TREATY (NPT)
C. STRATEGIC ARMS REDUCTION TREATY I (START I)
D. LIMITED TEST BAN TREATY (LTBT)
E. STRATEGIC ARMS LIMITATION TALKS II (SALT II)

D, E, C, A, B

*The correct answer is Option 4: D, E, C, A, B*

D. LIMITED TEST BAN TREATY (LTBT) - 1963
E. STRATEGIC ARMS LIMITATION TALKS II (SALT II) - 1972
C. STRATEGIC ARMS REDUCTION TREATY I (START I) -1991
A. STRATEGIC ARM REDUCTION TREATY II (START II) - 1993
B. NUCLEAR NON-PROLIFERATION TREATY (NPT) -1995

Explanation:

LIMITED TEST BAN TREATY (LTBT): Banned nuclear weapon tests in the atmosphere, in outer space and under water. Signed by the US, UK and USSR in Moscow on 5 August 1963. Entered into force on 10 October 1963.

STRATEGIC ARMS LIMITATION TALKS II (SALT-II): The second round started in November 1972. The US President Jimmy Carter and the Soviet leader Leonid Brezhnev signed the Treaty on the limitation of strategic offensive arms in Vienna on 18 June 1979.

STRATEGIC ARMS REDUCTION TREATY I (START-I): Treaty signed by the USSR President Mikhail Gorbachev and the US President George Bush (Senior) on the reduction and limitation of strategic offensive arms in Moscow on 31 July 1991.

STRATEGIC ARMS REDUCTION TREATY II (START-II): Treaty signed by the Russian President Boris Yeltsin and the US President George Bush (Senior) on the reduction and limitation of strategic offensive arms in Moscow on 3 January 1993.

NUCLEAR NON-PROLIFERATION TREATY (NPT): Allows only the nuclear weapon states to have nuclear weapons and stops others from aquiring 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.

NOTE: As per the given options, the most appropriate answer is option 4: D, E, C, A, B.

(Though NUCLEAR NON-PROLIFERATION TREATY (NPT) was signed in 1968, it was extended indefinitely in 1995. None of the given options follow a sequence in which 'B' comes immediately after D (which certainly has to be at the first place). Thus, accordingly B should be placed at last, as per the year in which it was extended indefinitely.]