Miguel, a calendar year taxpayer, files his 2013 Federal income tax return on April 1, 2017. The return showed $2,500 of tax due and Miguel pays that amount with the return. On March 1, 2019, Miguel discovers that he had made an error on his 2013 Federal income tax return and files an amended return requesting a refund. On May 15, 2019, the IRS denies Miguels refund claim on the grounds that the applicable statute of limitations has expired. Miguel disputes the denial of his refund claim.

In 2020, the IRS audits Miguels 2015 return and assesses an income tax deficiency against him on April 30, 2020. Miguel filed his 2015 return on July 27, 2016 under a valid extension of the original April 15, 2016 due date. Miguel disputes the assessment on the grounds that the statute of limitations has run.

a. Is Miguel correct in disputing the denial of his refund claim in 2019? Why? Are there any arguments that he might raise against the IRS? If so, what are they?

b. Is Miguel correct in disputing the assessment of income tax against him in 2020? Why? Are there any arguments that the IRS might raise against him? If so, what are they?

could you show me how you got to that answer? Thanks