Answer: a)
Groundwater polluted by the nearby landfills is an environmental concern.
Step-by-step explanation:
Due to the lack of sanitary disposal methods, people find open landfills the only source to dispose of their wastes. These waste materials contain chemical substances like phosphates, heavy metals, acids, nitrates, hydrocarbons, and human/animal wastes.
These landfills full of waste materials find their way to underground water, damaging its quality and making it toxic for humans and the environment.