Sume a calendar year individual with no fraud or substantial omission involved. a. The income tax return for 2018 was filed on February 19, 2019. b. The income tax return for 2018 was filed on June 25, 2019. c. The income tax return for 2018 was prepared on April 4, 2019, but was never filed. Through some misunderstanding between the preparer and the taxpayer, each expected the other to file the return. d. The income tax return for 2018 was never filed because the taxpayer thought no additio'nal tax was due.