Concept:Rainwater harvesting is the process of collecting and storing rainwater for direct use or to recharge groundwater.Explanation:It involves capturing rain from surfaces like rooftops and storing it in tanks or directing it into the ground. This helps conserve water and reduce pressure on municipal supplies. Common methods include rooftop rainwater harvesting and surface runoff harvesting. The stored water can be used for gardening, washing, and after treatment, for drinking. It also recharges groundwater aquifers, reduces flooding, and improves water quality. Rainwater harvesting is simple, cost‑effective, and especially useful in areas with water scarcity or erratic rainfall.Answer:Option B: Collection and storage of rainwater