The correct answer is (d). Oxygen (O2) is not a greenhouse gas. Greenhouse gases are gases that trap heat in the atmosphere, causing the planet to warm. The main greenhouse gases are water vapor (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ozone (O3), and chlorofluorocarbons (CFCs).
Water vapor is the most abundant greenhouse gas in the atmosphere, but it is not the most important contributor to climate change. This is because water vapor is a short-lived gas, meaning that it is quickly removed from the atmosphere by precipitation. Carbon dioxide is the second most abundant greenhouse gas in the atmosphere, and it is the most important contributor to climate change. This is because carbon dioxide is a long-lived gas, meaning that it can remain in the atmosphere for hundreds of years.
Methane is the third most abundant greenhouse gas in the atmosphere, and it is a more potent greenhouse gas than carbon dioxide. This means that methane traps more heat than carbon dioxide does. Nitrous oxide is the fourth most abundant greenhouse gas in the atmosphere, and it is also a more potent greenhouse gas than carbon dioxide. Ozone is a trace gas in the atmosphere, but it is a very potent greenhouse gas. Chlorofluorocarbons are synthetic gases that were once used in refrigerants and aerosol propellants. They are very potent greenhouse gases, and they were banned in the 1980s because they were destroying the ozone layer.
Oxygen is not a greenhouse gas because it does not trap heat in the atmosphere. Oxygen is a gas that is essential for life. It is used in cellular respiration, which is the process by which cells convert food into energy.