The answer to your question would be the last answer, starting with "Darkness, greed, and corruption" Charles Dickens creates this sense of darkness by the words he uses to describe the scene, such as "foul, cesspools, bad repute".
Judging by how it's used in the context, I would say C. A great number.
The allegory contains many forms of symbolism used to instruct the reader in the nature of perception. The cave represents superficial physical reality. It also represents ignorance, as those in the cave live accepting what they see at face value.
Hamlet's willingness to go with Rosencrantz and Guildenstern into a trap shows that he may be giving up. He knows the consequences he should face for killing Polonius and has not had the strength or courage to act against Claudius yet. It also is a point that he has descended further into a reality of the madness that he has been 'putting on'.
