Any taxpayer entitled to a carryback period under paragraph (1) may elect to relinquish the entire carryback period with respect to a net operating loss for any taxable year. Such election shall be made in such manner as may be prescribed by the Secretary, and shall be made by the due date (including extensions of time) for filing the taxpayer’s return for the taxable year of the net operating loss for which the election is to be in effect. Such election, once made for any taxable year, shall be irrevocable for such taxable year.