Election to apply subsection (a)(4)

Any State which satisfies the requirements of this section solely by reason of subsection (b) for a particular month or months in any 12-month period (described in such subsection) ending on or after June 30, 1982 , may elect, with respect to any month in any subsequent 12-month period (so described), to apply subsection (a)(4) as though the reference to December 1976 in such subsection were a reference to the month of December which occurred in the 12-month period immediately preceding such subsequent period.