(a) A registrant who has filed a claim for classification in Class 1-A-O or Class 1-O shall be scheduled for a personal appearance in accord with § 1648.4 before his claim is considered.

(b) A registrant who has filed a claim for classification in Class 2-D, Class 3-A, or Class 4-D, shall, upon his written request, be afforded an opportunity to appear in person before the board before his claim for classification is considered.

(c) Any registrant who has filed a claim for classification in an administrative class and whose claim has been denied, shall be afforded an opportunity to appear before the board if he requests that the denial of such claim be reviewed by the board.