In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index? 1. Carbon dioxide 2. Carbon monoxide 3. Nitrogen dioxide 4. Sulfur dioxide 5. Methane Select the correct answer using the code given below.

The National Air Quality Index (AQI) in India monitors eight specific pollutants—$PM_{10}$, $PM_{2.5}$, $NO_2$, $SO_2$, $CO$, $O_3$, $NH_3$, and $Pb$—making option (B) the only one containing exclusively correct pollutants. Carbon dioxide ($CO_2$) and Methane ($CH_4$) are excluded because they are primarily greenhouse gases associated with global warming rather than local air pollutants that cause immediate health impacts. The core concept tested is the distinction between criteria air pollutants used for health-based indices and greenhouse gases involved in climate change.