I believe the answer is D.
The guest are happy that they are able to wall off themselves from the world containing the Red Death. They planned to live and dance in luxury until disease died out. The only thing halting their excitement was the ominous clock chimes where all would stop until it ended.
...You could describe it as not just making or leaving tracks behind on mars, but in another way. As if you left tracks in everyones brains. (I don't know, at least I tried)
