Paul Perplexed's 20X1 income tax return was audited in January 20X3. The IRS assessed and Paul paid the tax, interest, and penalties on August 2, 20X3. On August 13, 20X3, Paul filed a claim for refund on Form 1040X to recover the full amount that he had paid. Paul consults you today to see what further action he can take to get his money back. He has lived at the same address for the entire period since he filed his claim for refund and he has never received any correspondence from the IRS either allowing or disallowing the claim for refund.

(A) What is the last date on which Paul can successfully bring a lawsuit against the IRS to recover his taxes, interest, and penalties that he paid in 20X3?

(B) What is the earliest date that Paul could file a lawsuit on the claim?