Oedipus' self-inflicted blindness symbolizes his foolishness and inability to see clearly what stood before him. Famed for his commonsense and clear thinking, Oedipus has been revealed all too human. Blinding himself is his way of taking responsibility for his part in his father's death and a symbol of new found wisdom. ;)
I think its <span>A. metaphor</span>
If you're meaning just a sentence with these two words, then:
She approached the significant hole in the wall, peering through it, a soft sigh of defeat passing her lips when she saw that the impenetrable vault she was meant to go wasn't there.
That help any?
