Which of the following situations requires a power of attorney?

A. Authorizing an individual to represent a taxpayer before the IRS

B. Allowing the IRS to discuss return information with a third party via the checkbox provided on a tax return or other document

C. Authorizing the disclosure of tax return information through Form 8821 - Tax Information Authorization, or other written or oral disclosure consent

D. Allowing the IRS to discuss return information with a fiduciary