(a) The applicant shall appear and, except as otherwise provided in §4.10, shall testify at the hearing and may cross-examine witnesses.

(b) The Secretary and others to whom notice has been sent pursuant to §4.7 shall be afforded an opportunity to appear and present evidence and cross-examine witnesses, at any hearing.

(c) In the discretion of the Commission or presiding officer, other witnesses may testify at the hearing.