In which situation can population growth make water crisis serious?

Correct answer: Population grows fast and water sources are limited

Direct answer: A. A water crisis becomes more likely when water demand increases faster than the available supply. Rapid population growth adds more households and more users. People need water for drinking, cooking, sanitation and other activities; farms and industries may also require water. If rivers, groundwater, reservoirs or other sources are limited, they cannot easily meet unlimited demand. The result can be shortage, competition and pressure on water sources. A correctly connects a rising population with limited supply. B is wrong because a declining population and increasing sources generally reduce population-related pressure. C is wrong because no population means no human demand in this situation. D is wrong because zero demand cannot create a demand-based crisis. The option does not claim population growth is the only cause; climate, management and pollution may also matter. Memory cue: crisis grows when demand rises beyond supply.