A sample of a piece of wood from a cliff dwelling in the southwest was analyzed for Carbon -14 content. What is a critical assumption(s) in this type of analysis? The Carbon 12 to Carbon 14 ratio is stable over time. All of the answers are assumptions that must be true for the analysis to be accurate. The decay rate of C14 is stable and does not change over time. The exchange of Carbon-12 and Carbon 14 stops when the tree producing the sample of wood died. Solution The decay rate of C14 is stable and does not change over time. Option b is the right answer .