"A Wedding Gift" is best considered a tragedy. Due to the sadness of it being placed around from a court case in the 1840s.
Nick was referring to the discovery of George's body. Holocaust is defined as a slaughter...... Myrtle, Gatsby, and Tom had each lost their lives for nothing....... they were the sacrifice of those who didn't care for anything or anyone beyond themselves.
Hope this helps!
The answer is: C. The next day