Which process is part of the carbon cycle?

Carbon cycle refers to an array of procedures by which the components of carbon are interchanged in the environment. One of the processes that are considered as the part of the carbon cycle is cellular respiration.  

In cellular respiration, the by-product is carbon dioxide, and the organisms get rid of this waste component by exhaling the gas back to the atmosphere. Each time one respires, one becomes the part of the carbon cycle, due to exhalation of carbon dioxide.  

b would be the right answer