Plate tectonics is referred to a geology theory, which explains the movement of earth’s lithosphere. This theory suggests that the earth’s lithosphere is made up of many plates, and these plates move on each other causing collision of the plates or sometimes separation of the landmasses.
Sometimes, the movements of the plate occur in such a way that the surface of the earth is buried underground. Even in normal circumstance, some of the surface materials buried underground. So, by studying the type of things existed on the surface in past, one can predict the abundance of a specific substance underground.
Hence, the correct answer is option b. – Plate tectonics.
Available oxygen
Available oxygen is the amount of oxygen present at a specific time that can be used in aerobic cellular respiration.
Aerobic cellular respiration is a metabolic process that occurs within the cells of organisms. In this process, oxygen is used in the mitochondria to chemically convert organic molecules such as glucose into adenosine triphosphate (ATP), with the release of water and carbon dioxide as waste products. Aerobic cellular respiration results in a larger amount of energy (ATP) which is used by the cell to perform its activities.
I believe it is a Pure Substance