(a) A respondent shall be afforded an opportunity to demonstrate that no action should be taken on the basis of a complaint by submitting, within fifteen (15) days from receipt of a copy of the complaint, a letter or memorandum setting forth reasons why the Commission should take no action.

(b) The Commission shall not take any action, or make any finding, against a respondent other than action dismissing the complaint, unless it has considered such response or unless no such response has been served upon the Commission within the fifteen (15) day period specified in 11 CFR 111.6(a).