Amy Is a Calendar Year Taxpayer Reporting on the Cash

Amy is a calendar year taxpayer reporting on the cash basis. Indicate which of the following income or expense items should not be included in her 2019 tax return.

A) On April 15, 2020, she makes a deductible contribution to her IRA for 2019.
B) She prepays half a year of interest in advance on her mortgage on the last day of 2019.
C) She pays all her outstanding invoices for standard business expenses in the last week of December 2019.
D) She sends out a big bill to a customer on January 1, 2020, even though she did all of the work in December of 2019.