Concept:Sedimentary rocks form from the compaction and cementation of sediments over time.Explanation:Shale is made of fine clay particles and tiny mineral fragments.These particles settle in layers, get compressed, and harden into a sedimentary rock.Graphite is a mineral form of carbon.Marble and schist are metamorphic rocks, changed by heat and pressure.Therefore, the only sedimentary rock in the list is shale.Answer:B. shale