(a) Consideration of record. Upon appeal from or review of an Initial Decision, the Commission shall consider the record as a whole or such parts of the record as are cited or as may be necessary to resolve the issues presented and, in addition, shall, to the extent necessary or desirable, exercise all the powers which it could have exercised if it had made the Initial Decision.

(b) Rendering of final decision. In rendering its decision, the Commission shall adopt, modify, or set aside the findings, conclusions, and order contained in the Initial Decision, and shall include in its Final Decision a statement of the reasons for its action and any concurring or dissenting opinions. The Commission shall issue an order reflecting its Final Decision.

(c) Except as otherwise ordered by the Commission, the Commission shall endeavor to file its Decision within ninety (90) days after the filing of all briefs or after receipt of transcript of the oral argument, whichever is later.