American water plant that has become a troublesome water weed in India is
Correct option is B. Eichhornia crassipes
Eichhornia crassipes , commonly known as water hyacinth , is an aquatic plant native to Amazon basin, known for it's highly problematic invasion outside it's native range. It forms dense mats in the water bodies, which causes the reduction in the oxygen for other organisms in the water body .
So the correct answer is 'Eichhornia crassipes'