Key Concept: Several invasive weeds have distinct common names tied to their history or effects — a direct recall fact.
Why it's correct: Parthenium hysterophorus is widely known as 'Congress grass' in India, an invasive weed causing dermatitis, respiratory issues, and yield loss through allelopathy.
Why others fail: Water hyacinth (Eichhornia), Lantana camara, and nutgrass (Cyperus rotundus) are all problem weeds too, but none is known by the name 'Congress grass.'