6. Which of the following statements concerning debt refundings is true?

a. Advance refundings do not result in immediate, direct retirement of existing long-term debt.

b. Often, resources of an irrevocable trust are used to service old long-term debt, even though the liability has been removed from the financial statements of the issuing government.

c. Both legal defeasance and in-substance defeasance may result in the removal of the old debt from the original issuer's balance sheet.

d. All of the above statements are true statements.

e. Items a and b only are true.