The Air Quality Index (AQI) is a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern.

In assessing the AQI:

Option 1 suggests considering Carbon Dioxide, Carbon Monoxide, and Nitrogen Dioxide. However, Carbon Dioxide is not usually considered in calculating AQI, despite being a greenhouse gas.

Option 2 indicates to consider Carbon Monoxide, Nitrogen Dioxide, and Sulfur Dioxide. These are the key pollutants and generally considered when calculating the AQI, making option 2 the correct answer.

Option 3 proposes considering Carbon Dioxide, Sulfur Dioxide, and Methane. As previously stated, Carbon Dioxide is not typically considered, and Methane, despite being a potent greenhouse gas, is also not normally included in AQI calculations.

Option 4 suggests considering all five gases, which is inaccurate given the reasons above.

Therefore, the correct answer is Option 2, which includes Carbon Monoxide, Nitrogen Dioxide, and Sulfur Dioxide, the three major pollutants tracked in AQI calculations.