Explanation:
"Insolvent" refers to a state where a person or organization is unable to pay their debts because their liabilities exceed their assets. In this context, it means that the speaker does not have enough money to settle the bill.

- A. overworked: This means working too much, which is unrelated to financial inability.
- B. bankrupt: This is correct. "Insolvent" is often used interchangeably with "bankrupt," which means being unable to pay off debts.
- C. unsettled: This could mean unresolved, but it doesn't specifically relate to financial inability.
- D. insoluble: This refers to something that cannot be dissolved or solved, which is unrelated to financial matters.
- E. affluent: This means wealthy or having a lot of money, which is the opposite of being "insolvent."

Therefore, B. bankrupt best conveys the meaning of "insolvent" in this context.