An agency may:
(a) Covenant as to the bonds to be issued, as to the issuance of such bonds in escrow or otherwise, and as to the use and disposition of the bond proceeds.
(b) Provide for the replacement of lost, destroyed, or mutilated bonds.
(c) Covenant against extending the time for the payment of its bonds or interest.
(d) Redeem the bonds, covenant for their redemption, and provide the redemption terms and conditions.