Ans. (c) Eichhornia (water hyacinth) has been introduced in India to check water pollution, as this weed absorbs mercury, cadmium, lead, and nickel from sewage water lt is considered as the world's most problematic weed as it is on invasive species. If not controlled, water hyacinth covers the intro pond or ake and impacts water flow. Blocks Sunlight acts as prime habitat for mosquito (vector) snails host for flatworm and starves the water of oxygen.
