Final answer:
Members of the biosphere regularly exchange carbon with the atmosphere, the oceans, and fossil fuels below ground.
Step-by-step explanation:
Members of the biosphere regularly exchange carbon with all of the above mentioned in the options: the atmosphere, the oceans, and fossil fuels below ground.
The atmosphere is a major reservoir of carbon in the form of carbon dioxide. Carbon dioxide is exchanged between the atmosphere and living organisms through the process of respiration and photosynthesis.
The oceans are also a significant reservoir of carbon, and carbon is exchanged between the atmosphere and the ocean through processes like diffusion and ocean circulation.
Fossil fuels, which are found below ground, also contain carbon. When these fossil fuels are burned, carbon is released into the atmosphere, completing the carbon cycle.