Final answer:
Douglas' theory of sacred contagion can best be described as religion being a system of classification, where anything that does not fit into that system is taboo.
Step-by-step explanation:
Douglas' theory of sacred contagion can best be described as option C, which states that religion is a system of classification, and anything that does not fit into that system is taboo. In her book Purity and Danger (1966), Douglas analyzed the influence of cultural ideas about things that were considered 'dirty' or 'impure' on religious beliefs. She examined a wide range of taboos, such as rules against eating certain foods or engaging in sex at certain times or with certain persons. These rules, like the kosher dietary rules observed by Jews, reflect a system of classification where certain objects or practices are considered outside the norm or 'matter out of place,' leading to their classification as taboo.