The main advantage of Rain Water Harvesting (RWH) is the recharge of groundwater. This means that when rainwater is harvested and stored, it infiltrates into the ground, replenishing the underground water sources such as wells and aquifers. By recharging groundwater, RWH helps in maintaining the water table and prevents the depletion of underground water resources. This is particularly important in areas where the availability of clean and safe drinking water is a concern. Option-1 is correct because Recharging groundwater is the primary benefit of rainwater harvesting. Alert - correct answer should be "The main advantage of Rain Water Harvesting (RWH) is the recharge of groundwater. This means that when rainwater is harvested and stored, it infiltrates into the ground, replenishing the underground water sources such as wells and aquifers. By recharging groundwater, RWH helps in maintaining the water table and prevents the depletion of underground water resources. This is particularly important in areas where the availability of clean and safe drinking water is a concern."