“ The Secretary of Energy, or his delegate, shall expeditiously conduct a public inquiry as to what other types of heavy crude oil, if any, should be exempted from price controls adopted pursuant to the Emergency Petroleum Allocation Act of 1973, as amended, in order to maintain or increase production of such crude oil. Upon completion of that inquiry, the Secretary shall make a recommendation to the President as to what other types of heavy crude oil, if any, should be exempt from price controls. ”