The option for this question are:
A) teach a lesson about financial responsibility.
B) illustrate the idea of demanding what one is due.
C) provide information about American economics.
D) suggest ways to pursue the American dream.
Answer: B) illustrate the idea of demanding what one is due.
Step-by-step explanation: A metaphor is a direct comparison between elements that aren't obviously related, in order to create an image in the reader's mind. In the given excerpt from Martin Luther King Jr.'s "I Have a Dream" speech we can see the use of the metaphors "check" and "promissory note" to give the idea of black people having the right to receive this payments but only receiving checks marked with "insufficient funds", this metaphor is used to refer to the right of equality according to the Declaration of Independence.