Question

which of the following gas is emitted during plant respiration, animal respiration, and auto and factory emissions?
n₂o
no₂
o₂
co₂

Explanation:

During plant and animal respiration, glucose is broken - down in the presence of oxygen to release energy, and carbon - dioxide ($CO_2$) is a by - product. Auto and factory emissions also release carbon - dioxide as a result of burning fossil fuels. $N_2O$ and $NO_2$ are nitrogen - containing pollutants mainly from industrial and agricultural sources. Oxygen ($O_2$) is taken in during respiration and is a product of photosynthesis, not an emission in the context of the question.

Answer:

$CO_2$