The correct option is B Eichhornia crassipes
Ornamental plants are grown for decorative purposes.
Eichhornia crassipes was introduced in Bengal, India because of its beautiful flowers and shapes of leaves but turned out to be an invasive weed draining oxygen from the water bodies and resulted in the death of many fish. Fish is a supplement food in Bengal and due the fish scarcity produced in Bengal due to Eichhornia, it is also called as “Terror of Bengal”
Parthenium hysterophorus is not native to India, it was introduced to India along with wheat as a contaminant. Prosopis juliflora was introduced in India for fuel and fodder.
Trapa spinosa is a medicinal plant.
Hence, option b is correct.