Which statement best describes carbon cycle steps?

• A. Carbon moves only in rocks.
• B. Animals produce carbon from nothing.
• C. Photosynthesis uses oxygen to create carbon.
• D. Plants absorb CO2; with water they make substances for growth; the process of photosynthesis transforms carbon dioxide into sugars, which later are eaten by animals or insects that use it for their own needs. Those animals reinject carbon dioxide into the atmosphere by breathing or when they die it is being returned to the soil by the decomposition process.

Answer: (D)

The carbon cycle moves carbon through the air, plants, animals, and soil using energy from the sun and processes like photosynthesis, growth, respiration, and decomposition. Plants take in carbon dioxide from the atmosphere and, with water, convert it into sugars that build their tissues. When animals eat plants, carbon moves along the food chain, and they release carbon dioxide back into the air when they breathe; when organisms die, decomposition returns carbon to the soil. Over time, some carbon is stored in soils and rocks, while other portions cycle back to the atmosphere as CO2. This description captures how carbon travels through the main reservoirs and processes of the cycle, which is why it’s the best fit. The other statements miss or misstate parts of the cycle: carbon isn’t moved only in rocks; animals don’t create carbon from nothing; photosynthesis uses carbon dioxide (not oxygen) to form sugars, releasing oxygen.