Thunder is caused by the extremely rapid expansion of air around a bolt of lightning due to the very high temperature. It is also caused by the change of pressure around a lightning bolt.
Hope that helped you.
The answer would be A. carbohydrates (carbs) because carbs are generally composed of sugars and glucose (as an example) has the ratio between carbon, hydrogen and oxygen in a 1:2:1 ratio in its form: C6H12O6
1.) carbon dioxide
2.) sulfur dioxide
3.) nitrogen oxides