Which best describes the process of carbon-14 dating? carbon-14 decays at a constant rate, and scientists measure the amount of carbon in a fossil to determine its age. scientists use a biological compound found in all living things to track carbon-14 over time. scientists compare the carbon-14 levels in present humans with human fossils. scientists find carbon-14 in the rugged desert of ethopia and implant it into fossils, which then show a constant rate of decay.