Answer:
it's the fourth one
Explanation:
because rung is not the correct grammar and the first one is not in the correct order of sentence
The answer should be D. was, singular.
In Oedipus rex, sphinx symbolises the Oedipus courage, when Oedipus courageously without being scared of the death accepted the riddle of sphinx. He gave the correct answer of his riddle. Which cause him disappear and he died at that very moment.So it was the courage that caused a great set back to the death.