Which of the following processes plays an important role in cycling carbon, nitrogen, and phosphorus?

photosynthesis
transpiration
decomposition
respiration

The process that plays an important role in cycling carbon, nitrogen, and phosphorous is decomposition.

Explanation:

Decomposition is a process whereby predominantly anaerobic bacteria degrade organic matter under low oxygen or anoxic conditions. In the case of putrefaction, proteins in particular are chemically degraded to produce unpleasantly odorous and toxic compounds such as hydrogen sulphide, indole, skatole and mercaptans. In other words, it is the degradation of organic molecules by the action of microorganisms.