The following persons are subject to an audit of books, accounts, or records: before the expiration of the period of retention under subsection (c) of this section, a person who submits cost and price information under § 13-220 of this article, if the books, accounts, or records being audited are reasonably connected with the cost and price information; a contractor or subcontractor under a procurement contract if, from an audit of a cost-type contract, the unit has reason to believe that costs have been inappropriately assigned to the cost-type contract from a fixed-price contract; and a contractor or subcontractor under a procurement contract that: was awarded by a method other than competitive sealed bids; and is not a firm fixed-price procurement contract. An audit under this section may be conducted by: the Department of Legislative Services; a unit engaged in procurement; or as authorized by law, any other unit. A person subject to an audit under subsection (a) of this section shall keep books, accounts, and records for: at least 3 years after the day on which the person receives final payment under a procurement contract or a subcontract; or if longer, the period required under the procurement contract.