In Mama Lola: a Vodou Priestess in Brooklyn, Karen McCarthy

In Mama Lola: A Vodou Priestess in Brooklyn, Karen McCarthy Brown studied practitioners of the Vodou religion living in the United States. However, she went far beyond the usual role of scientific observer and became a member of the religious group she was studying. She also gave her key informant veto power over certain elements of her work. Why would this be helpful?

A) It helped her learn all the secrets that practitioners of Vodou would not tell outsiders.
B) It gave her better insight into how to convert practitioners away from Vodou.
C) It helped her set aside preconceived notions about Vodou to understand it on its own terms.
D) It would not be helpful; without doubt, it crippled her ability to make objective judgments.