((a)) The Secretary concerned may provide a system of parole for offenders who are confined in military correctional facilities and who were at the time of commission of their offenses subject to the authority of that Secretary.
((b)) In a case in which parole for an offender serving a sentence of confinement for life is denied, only the President or the Secretary concerned may grant the offender parole on appeal of that denial. The authority to grant parole on appeal in such a case may not be delegated.