(a) The Office of Planning and Budget shall be: (1) The principal state agency for coordinating planning and programming for comprehensive development; (2) The state agency responsible for preparing, maintaining, and furnishing official demographic data for the state; and (3) The principal state agency for statistical coordination and standardization. (b) The office may apply for and receive grants-in-aid, contributions, and any other forms of financial or other assistance from any source, public or private, for the purposes of this Code section and Code Sections 45-12-172 and 45-12-177. (c) The office shall serve as the state agency for all federal programs which require state designation of a single clearing-house if federal or state law does not provide for another state agency or if the Governor does not designate another state agency by executive order.