Answer:
a. The waste and corruption of the wealthy.
Step-by-step explanation:
The valley of ashes is meant to represent the waste and corruption of the wealthy class. This goes with one of the most important themes of the novel: the decadence of the wealthy. In this novel, the author is very critical of the impact that wealth has on society. He believes that the rich have become so preoccupied with the accumulation of money (a type of "American Dream")