Alice and Brian Campbell requested an extension of time to file their 2020 income tax return. Provide the filing date for their return for each scenario. a. The return is e-filed on October 10, 2021. b. The return is mailed to an IRS campus on October 14, 2021. It is received by the IRS on October 16, 2021 and processed on October 20, 2021. c. The return is hand delivered to an IRS employee on October 20, 2021