The correct option is 1, 2, and 3 because the combustion of coal in thermal power plants releases a variety of pollutants. Carbon dioxide (CO2) is a primary greenhouse gas resulting from the burning of coal, contributing significantly to climate change. Additionally, coal combustion releases oxides of nitrogen (NOx) and sulfur (SOx) due to the reaction of nitrogen and sulfur present in the fuel with oxygen during high-temperature combustion. These emissions contribute to air pollution, acid rain, and various health issues, underscoring the environmental and health impacts of coal-based energy generation, concepts that are critical in UPSC context concerning sustainable energy and environmental governance.