How does de-icing roads with salt negatively impact the environment?
a. the road salt attracts deer that are then hit by motor vehicles.
b. it removes necessary salt from the local water courses.
c. the high salinity of the surface runoff is harmful to freshwater ecosystems.
d. the salt harbors salt eating bacteria that are toxic to animals.

c. the high salinity of the surface runoff is harmful to freshwater ecosystems.
the runoff of saline soil in the nearby fresh water sources will increase the salinity of water. It will badly affect aquatic plants and animals. the higher concentration of salt will adversely affect the metabolic activities. It may even lead to exosmosis and eventual death of organisms.