What would be the most effective solution to avoid future conflicts among the nations?

The correct answer is (C) To conserve water.

• Logical Principle: The question pertains to the root cause of potential future international conflicts. Given the finite nature of natural resources, the depletion of water is a major geopolitical driver for instability. Strategic resource management serves as a preventive measure against conflict.
• Deductive Reasoning: While diplomacy (United Nations) and arms reduction (Option A) are important, they address the symptoms or enforcement of peace rather than the primary scarcity issues. Water scarcity is a tangible threat multiplier. Conserving water directly reduces the competition and the necessity for regional aggression over shared aquifers or river systems, thereby mitigating the root cause of potential future strife.
• Comparative Analysis: Option (A) is idealistic but practically difficult to enforce universally. Option (B) implies water is a commodity to be divided, whereas (C) (conservation) addresses the scarcity itself, preventing the conflict at the origin. Option (D) represents an institutional mechanism, which is reactive, whereas conservation is a proactive policy that prevents the conflict from manifesting.