Which of the following processes produces carbon dioxide during decomposition?

The process that produces carbon dioxide during decomposition is primarily the breakdown of organic matter by bacteria and other microorganisms. During the decomposition process, bacteria consume organic material, which results in the release of carbon dioxide as a byproduct of their metabolic activities.

This biological process is vital for nutrient recycling in ecosystems, as it converts complex organic compounds into simpler substances. The organic matter is decomposed into carbon dioxide, water, and other simpler molecules, returning essential nutrients to the soil and atmosphere, which can then be utilized by plants.

While respiration and photosynthesis involve carbon dioxide in different aspects of the carbon cycle, they do not specifically refer to the process of decomposition. Therefore, the decomposition by bacteria is the correct answer, as it specifically highlights the role of microbial action in releasing carbon dioxide during the breakdown of organic materials.