Final answer:
The Mark Twain excerpt satirizes the human tendency to blame others for their own mistakes, depicted through a protagonist's fear of being wrongly blamed for the confusion over the value of a bank note. The correct option is D. the nature of people to blame others for their own mistakes or shortcomings.
Step-by-step explanation:
In the excerpt from Mark Twain's "The £1,000,000 Bank-Note" the passage satirizes the nature of people to blame others for their own mistakes or shortcomings. Twain humorously illustrates how individuals tend to direct their frustration and anger towards others, rather than acknowledging their own errors. This aspect of human nature is depicted through the panicked thought process of the protagonist who expects blame for a mistake not of his doing, but instead due to the fault of those who mistook the value of the bank note.