All banks, trust companies, bankers, savings banks and institutions, savings and loan associations, investment companies, and other persons carrying on a banking or investment business and all executors, administrators, curators, trustees, and other fiduciaries may legally invest any sinking funds, moneys, or other funds belonging to them or within their control in any bonds or other obligations issued by a municipality pursuant to this chapter or by any urban renewal agency or housing authority vested with urban renewal project powers under section 40-58-15. However, the bonds and other obligations must be secured by an agreement between the issuer and the federal government in which the issuer agrees to borrow from the federal government and the federal government agrees to lend to the issuer, prior to the maturity of the bonds or other obligations, moneys in an amount which together with any other moneys irrevocably committed to the payment of interest on the bonds or other obligations will suffice to pay the principal of such bonds or other obligations with interest to maturity thereon, which moneys under the terms of the agreement are required to be used for the purpose of paying the principal of and the interest on the bonds or other obligations at their maturity. The bonds and other obligations are authorized security for all public deposits. This section does not relieve any person of any duty of exercising reasonable care in selecting securities.