Concept:Schistosomiasis is spread through freshwater snails, which act as intermediate hosts for the parasite.Explanation:The parasites that cause Schistosomiasis complete part of their life cycle inside freshwater snails.Infected snails release larvae into water, and humans become infected through skin contact with this water.Therefore, controlling the disease focuses on breaking the cycle by removing the snails from water bodies.Destroying water snails and water weeds reduces the snail population and limits the spread of the parasite.Answer:A. destroying water snails and water weeds