If you have been working through Assumption questions and building a reasoning process, this is a useful question to pause on. Not because the answer is difficult, but because the argument tests several things that are easy to get right accidentally. Here is the setup. A group of researchers wants to learn about an ancient people who left few obvious traces in the historical record. Their plan involves hiring the few remaining shamans of a modern indigenous group, who are believed to be descended from these ancestors. These shamans were taught the locations of ancestral sites during their traditional training as youths. The researchers expect that the shamans' knowledge of traditional customs will also help them interpret whatever sites they find. The question asks which of the following is an assumption on which the success of the plan depends. If you solved this question already, here are four things worth checking against your process. If you have not, attempt it first, then come back.…