Any person required to furnish a bond to the Government has the option, instead of furnishing a surety or sureties on the bond, of depositing certain United States bonds or notes in an amount equal at their par value to the penal sum of the bond (the Act of February 24, 1919 (31 U.S.C. 9303) and Treasury Department Circular No. 154 dated July 1, 1978 (31 CFR Part 225)). In addition, a duly executed power of attorney and agreement authorizing the collection or sale of such United States bonds or notes in the event of default of the principal on the bond shall accompany the deposited bonds or notes. The contracting officer may—