Correct answer: (c) Eichhomia

Explanation:

The world’s most problematic aquatic weed is water hyacinth (Eichhornia crassipes) also called Terror of Bengal. It were introduced into India for their lovely flowers (mauve coloured) and shape of leaves. They grow abundantly in eutrophic (nutrient rich) water bodies. Eichhornia caused havoc by their excessive growth by causing blocks in our water ways and lead to an imbalance in the ecosystem dynamics of the water body. They grow faster than our ability to remove them.