The question below consists of a set of labelled sentences. Out of the four options given, select the most logical order of the sentences to form a coherent paragraph.

P: And the victims are likely to be the poorest of the poor as well as the very sources of water- rivers, wetlands and aquifers.
Q: In India, water conflicts are likely to worsen before they begin to be resolved.
R: Till then they pose a significant threat to economic growth, security and health of the ecosystem.
S: Water is radically altering and affecting political boundaries all over world, between as well as within countries.