The respondent may serve and file an answer to the petition within eight days of service of the petition if service was personal, or within thirteen days of service of the petition if service was by mail, unless a different time is fixed by the administrative law judge. In the discretion of the administrative law judge, the respondent may be required to serve and file an answer. Failure to file an answer where required, may result in sanctions, including those specified in 48 RCNY § 1-33(e).