In Class 1-D-E shall be placed any registrant who:
(a) Is a student enrolled in an officer procurement program at a military college the curriculum of which is approved by the Secretary of Defense; or
(b) Has been enlisted in the Delayed Entry Program (DEP) at least ten days prior to his scheduled induction date; or
(c) Has been transferred to a reserve component of the Army, Navy, Air Force, Marine Corps or Coast Guard after a period of extended active duty, which was not for training only.