TOEFL Listening: TPO-TOEFL阅读TPO - 75T31R1FI27621ZGN$

Why does the author mention "secret ceremonies"? A. To present a common opinion held by many scholars B. To suggest a similarity between two opinions held by scholars C. To suggest a possible explanation for a weakness in an opinion expressed in the passage D. To give evidence that contradicts a major opinion expressed in the passage