Final answer:
The biosphere contains the most carbon matter, with the atmosphere being the most recognizable reservoir of carbon.
Step-by-step explanation:
The biosphere, which includes the interaction of the lithosphere, hydrosphere, and atmosphere, contains the most carbon matter. While carbon can be found in ocean water, rocks, and sediment, the atmosphere is the most recognizable reservoir of carbon. Carbon appears in various forms in different parts of the carbon cycle, including carbon dioxide in the atmosphere.