Fracking uses highly pressurized fluids, such as water mixed with sand and chemicals, to drive open cracks that exist in underground rock. Which statement best describes an environmental consequence of this process? A. Chemicals added to the liquid can contaminate groundwater.
B. Wastewater is contaminated with oil and becomes sludge in landfills.
C. Water vapor is released into the air, which is considered a greenhouse gas.
D. Heavy metals are released into surrounding soil, poisoning local vegetation.