The correct answer is A. Carbon dioxide and Methane.
The greenhouse effect is a natural process that warms the Earth’s surface. Gases in the atmosphere, such as water vapor, carbon dioxide, methane, nitrous oxide, ozone, and some artificial chemicals, absorb energy from sunlight and re-emit it as heat. This process helps to keep the Earth warm and habitable.
However, human activities are increasing the levels of greenhouse gases in the atmosphere. This is causing the greenhouse effect to become stronger, which is leading to global warming.
Carbon dioxide is the most important greenhouse gas. It is produced by burning fossil fuels, such as coal, oil, and natural gas. Methane is another important greenhouse gas. It is produced by natural processes, such as decomposition, and by human activities, such as agriculture and waste management.
Ammonia and ozone are not greenhouse gases. They are both important pollutants, but they do not contribute to the greenhouse effect.
Carbon monoxide and sulfur dioxide are also pollutants, but they are not greenhouse gases either.
Carbon tetrafluoride and nitrous oxide are greenhouse gases, but they are not as important as carbon dioxide and methane.
Therefore, the correct answer is A. Carbon dioxide and Methane.