Question

which process in the carbon cycle is directly driven by sunlight?
combustion
decomposition
cellular respiration
photosynthesis

Explanation:

Photosynthesis is the process in the carbon cycle that directly uses sunlight. Plants take in carbon dioxide ($CO_2$) and water ($H_2O$), and with the energy from sunlight, they produce glucose ($C_6H_{12}O_6$) and oxygen ($O_2$). The chemical equation for photosynthesis is

$$6CO_2 + 6H_2O + \text{sunlight} ightarrow C_6H_{12}O_6 + 6O_2$$

. Combustion is a reaction of a substance with oxygen (usually from the air) that releases energy, often in the form of heat and light. Decomposition is the breakdown of organic matter by decomposers (like bacteria and fungi). Cellular respiration is the process by which cells break down glucose to release energy, and it does not directly use sunlight.

Answer:

Photosynthesis