Concept:Drip irrigation is a water-efficient method that delivers water slowly and directly to the roots of plants.
Explanation:This system uses tubes, valves, and emitters to drip water at the base of each plant.
It saves water by reducing evaporation and runoff compared to traditional irrigation.
The goal is to conserve water, especially in dry regions.
Rainwater harvesting collects and stores rain – it is different from drip irrigation.
Water purification removes harmful substances from water, not related to drip irrigation.
Sublimation is a physical change from solid to gas, with no connection to irrigation.
Thus, drip irrigation is a technique for water conservation.
Answer:B. Water conservation