Final answer:
The conclusion that can be drawn from the text is option (b), indicating that either Nui Fen or Zheng told on them, as there is insufficient information to definitively claim either option (a) or (c).
Step-by-step explanation:
The text presents various narratives and commentaries, some of which are based on oral traditions and others on historical records or allegorical writings. Given the information that either Nui Fen or Zheng could have been responsible for telling on individuals, the conclusion that can be drawn is option (b), that Nui Fen or Zheng told on them.
We cannot conclude that both told (option a) or that neither did (option c), as nothing in the text definitively indicates that both were involved or clears them both of the act. The text suggests a level of ambiguity and uncertainty surrounding historical narratives and the reliability of sources. Therefore, the safe assumption lies with the one already given in the original question.