who, on or after the date on which such person became entitled to educational assistance under this chapter ceases to be a member of the Selected Reserve during the period beginning on
October 1, 1991, and ending on
December 31, 2001, or the period beginning on
October 1, 2007, and ending on
September 30, 2014, by reason of the inactivation of the person’s unit of assignment or by reason of involuntarily ceasing to be designated as a member of the Selected Reserve pursuant to
section 10143(a) of this title,