Which process involves carbon moving directly from the biosphere into the geosphere? (1 point) the photosynthesis of a plant the weathering of rocks by a river the decomposition of plants on the forest floor the eruption of a volcano

The correct answer is: **the weathering of rocks by a river** **Explanation:** - **Weathering of rocks by a river** involves the chemical breakdown of minerals in rocks, which can incorporate carbon dioxide from the atmosphere into carbonate minerals. This process effectively transfers carbon from the biosphere (through atmospheric CO₂ influenced by biological activity) into the geosphere by locking carbon in solid mineral forms. The other options do not involve a direct transfer of carbon from the biosphere to the geosphere: - **Photosynthesis of a plant** transfers carbon from the atmosphere to the biosphere. - **Decomposition of plants on the forest floor** typically releases carbon back into the atmosphere or soil. - **Eruption of a volcano** releases carbon from the geosphere to the atmosphere.