The Board shall, within 100 days after the filing of a complaint, determine, based on the facts and after consultation with the Office of the Attorney General, whether reasonable cause exists to believe that a discriminatory housing practice has occurred or is about to occur, unless it is impracticable to do so or unless the Board has approved a conciliation agreement with respect to the complaint. If the Board is unable to determine whether reasonable cause exists to believe that a discriminatory housing practice has occurred or is about to occur within 100 days after receipt of the complaint, the aggrieved person and the respondent shall be notified in writing of the reasons therefor.