(a) If revenue obligations issued under this chapter state that they are secured in whole or in part by a pledge of the proceeds from a contract, including a lease contract, a copy of the contract and of the proceedings authorizing the contract must be submitted to the attorney general with the record relating to the issuance of the obligations.
(b) The approval by the attorney general of the obligations is approval of the contract.
(c) After approval, the contract is incontestable except for forgery or fraud.