The correct answer is D. Decomposition
Step-by-step explanation:
Carbon dioxide is a type of gas that is composed of one atom of carbon and two atoms of oxygen. This substance is released to the Earth atmosphere through different processes that include respiration, volcanoes activities, human activities, and decomposition. In the case of the decomposition, this refers to the process bodies of organisms suffer after death that involves chemical process including accumulation of carbon dioxide and release of carbon dioxide and other gases to the atmosphere. Considering this, the process that adds carbon dioxide to the atmosphere is the decomposition.