(a) The presiding officer may, in his discretion, provide for oral argument by parties at the end of the hearing. Such argument, when permitted, may be limited by the presiding officer to the extent necessary for the expeditious disposition of the proceeding.

(b) The presiding officer shall announce at the hearing a reasonable period of time within which any party may file with the presiding officer proposed findings and conclusions and written arguments or briefs, which are based upon the record and citing where practicable the relevant page or pages of the transcript. If a party filing a brief desires the presiding officer to reconsider any objection made by such party to a ruling of the presiding officer, he shall specifically identify such rulings by reference to the pertinent pages of the transcript and shall state his arguments thereon as a part of the brief.

(c) Oral or written arguments shall be limited to issues arising from direct testimony on the record.