The right answer is D.
The phosphorus cycle is unique among the major biogeochemical cycles because it does not have a gaseous component; it hardly affects the atmosphere.
The sulfur cycle is the biogeochemical cycle of the different forms of sulfur. Sulfur is an essential element of life that, like carbon, phosphorus, oxygen, nitrogen or even water, has its own life cycle. Indeed, sulfur is present everywhere on Earth, atmosphere, oceans, continents, but also in all living beings in the form of organic molecules: sulfur-containing amino acids constituting proteins (methionine and cysteine).
