Answer:
b. air pollution, corrosion of pipes, and may be toxic to fish
Explanation:
Use of earth heat to generate electrical energy through geothermal power plants is known as geothermal energy. There are certain disadvantages associated with geothermal power generation. One such problems is air pollution. Steam from the Earth brings up heavy metals such as Sulfer, Radon Salts and toxic gases which pollute environment. In the process of energy production, hazardous sludge produced which contaminate soil and water. Due to presence of heavy metals it corrodes pipes. Geothermal plants should be constructed with utmost care otherwise it greatly impact on local environment.