Which of the following treaty was rejected by India as discriminatory as it prevented only non-nuclear countries from acquiring nuclear weapons?

The correct option is Non-Proliferation Treaty.

Detailed Explanation:
The Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the Non-Proliferation Treaty (NPT), is an international treaty whose objective is to prevent the spread of nuclear weapons and weapons technology, to promote cooperation in the peaceful uses of nuclear energy, and to further the goal of achieving nuclear disarmament.

India refused to sign the NPT because it viewed the treaty as inherently discriminatory. The key reasons for India's stance include:
1. Division of States: The treaty divides the world into "Nuclear-Weapon States" (NWS) and "Non-Nuclear-Weapon States" (NNWS). The NWS are defined as countries that had manufactured and exploded a nuclear weapon prior to January 1, 1967 (namely, the United States, the Soviet Union/Russia, the United Kingdom, France, and China).
2. Asymmetric Obligations: The treaty restricts non-nuclear countries from acquiring or developing nuclear weapons, but it does not impose any legally binding, time-bound obligations on the existing nuclear-weapon states to disarm or dismantle their own arsenals.
3. Legitimizing Inequality: India argued that this framework created a divide between "nuclear haves" and "nuclear have-nots," securing the nuclear monopoly of a few select nations. Consequently, India chose not to sign the NPT, advocating instead for global, non-discriminatory, and complete nuclear disarmament.