Explanation:

- Neem: This tree is environmentally beneficial. It provides shade, improves soil fertility, and has medicinal properties.

- Eucalyptus: Correct Answer: Eucalyptus trees can be harmful to the environment. They consume large amounts of water, which can deplete groundwater. In some ecosystems, they can outcompete native species and potentially alter soil chemistry.

- Babool: Known for its drought tolerance, this tree is also valued for preventing soil erosion and for its role in reforestation.

- Banana: This plant is not dangerous for the environment. It provides food and its broad leaves contribute to ecosystem diversity.