Amy is a calendar-year taxpayer reporting on the cash basis. Please indicate how she should treat the following items for 2018: 

a. She makes a deductible contribution to an IRA on April 15, 2019 

b. She has made an election to accrue the increase in value of savings bonds even though the increase is not received in cash. 

c. She prepays half a year of interest in advance on her mortgage on the last day of 2018. 

d. She pays all of her outstanding invoices for standard business expenses in the last week of December. 

e. She sends out a big bill to a customer on January 1, 2019, even though she did all of the work in December of 2018.