A city issued bonds on July 1. Interest of $600,000 is payable the following January 1. On December 31, the city transfers the required $600,000 from its general fund to its debt service fund. On its December 31 debt service fund statement of revenues, expenditures, and changes in fund balance, the city :______

a. Must report interest expenditure of $0
b. Must report interest expenditure of $600,0000
c. Must report interest expenditure of $500,000
d. May report interest expenditure of either $0 or $600,000