The answer would be the first choice or A. "Original ideas that are <em>not</em> your own."
Any piece of information that does not belong to you would require a citation, otherwise it would be considered <em>plagiarism. </em>B and C are incorrect because both of those things belong to you, and therefore don't require citation. D is also incorrect because a general fact doesn't belong to any one person. For example, if you wanted to include the information that dogs can't eat chocolate, that wouldn't require a citation because that is general knowledge that most people are aware of.
Answer:
He is a prophet, and he gives us several signs of his power even before he tells us his prophecy. One of the reasons why we know that he is indeed a prophet is from the interpretations that he makes of signs. The signs tell him that the gods do not approve of Creon's behaviour.
hope it hwlps