The correct answer is participant observer
Participant observation is an excellent methodological resource for research because it allows a more dense insertion in the practices and representations experienced by the respective religious expressions chosen for study. By this method, the researcher closely follows the event of his investigation; the most constant incursions into the group's cults and everyday situations, allow you to further decode the imaginary, vocabulary, symbols and valid rites and coherent for their respective supporters, with greater correspondence to the way in which members experience their belief.