Can somebody please explain why A is wrong for this question?

Hi Jing Jing, thanks for the question! Answer choice A is incorrect because we don't know that Bettelheim believes that children are uninterested in inflexible tenets of moral instruction. The idea of "inflexible tenets of moral instruction" is brought up at the end of the third paragraph with reference to how people with different cultural assumptions and expectations might interpret the tales. I hope this helps. Please let me know if you have any other questions.