Final answer:
The organic portion of the lithosphere is primarily made up of the remains of living creatures found in materials such as oil shale and certain types of limestone, with the organic material originating from biological processes.
Step-by-step explanation:
The materials that make up the organic portion of the lithosphere primarily consist of the remains of living creatures, which refers to fossilized plants and animals, and can be found in substances such as oil shale and certain types of limestone. Some of these organic-rich rocks, like bioclastic or fossiliferous limestone, result from the accumulation of biological debris. As for the other materials given, sodium bicarbonate and apatite do not qualify as organic as they are inorganic chemical compounds, living creatures are not considered a part of the lithosphere's composition, and bakelite is a synthetic polymer not found naturally in the lithosphere.
Furthermore, although some compounds containing carbon like carbonates and bicarbonates are found in the lithosphere, these are not classified as organic materials. Limestone may contain fossilized remains but in itself is considered inorganic unless specific organic components are present in its matrix. The term 'organic' in a geological sense often refers to carbon-containing compounds that are derived from organisms, or assembled via biological processes.