Human behavior which can be seen by other people and observed by other people is usually also the behavior which is often subject to measurement, control, and experimentation in psychological experiments. The field which does this is psychology.
Answer:
i think it should be a or c
During the respiration of plants, animals, and organisms that bring about decomposition, carbon dioxide is returned to the atmosphere. The combustion of fossil fuels (e.g. coal and peat) also releases carbon dioxide into the atmosphere.