What does 'water war' mean?

The correct answer is Option 1 - Water war means conflict over the rights of economic exploitation of the water.

Water is another crucial resource that is relevant to global politics. Regional variations and the increasing scarcity of freshwater in some parts of the world point to the possibility of disagreements over shared water resources as a leading source of conflicts in the 21st century. Some commentators on world politics have referred to ‘water wars’ to describe the possibility of violent conflict over this life-sustaining resource. Countries that share rivers can disagree over many things.