Your contractor complains that it has not been paid for an invoice submitted several months ago. Which one of the following is a potential cause of this problem?

DFAS Regional Finance Center failed to submit a voucher summary to the Treasury

Items or services cited in the invoice could not be verified by the Administrative Contracting Officer

Procuring Contracting Officer delayed award of the contract due to a protest

Disbursing Office matches the certified contractor payment request up to one or more existing obligations in the accounting system.