Answer:
Evolutionary approach.
Step-by-step explanation:
An evolutionary approach is a pattern or system of using evolutionary ideas in studying and learning about an individual's cultural beliefs and behavior, habits etc. This approach is used by anthropologists to try and explain how humans evolve through the ages.
In taking the "primitive" societies as the early stage in the development of religions, anthropologists are using the evolutionary approach. In this way, they are turning to the evolution process/ system to determine and learn about religious development.