The Board shall review the complaint and any response. If the information in the complaint and response is sufficient for making a determination, within 30 days after receiving the response the Board shall issue a written opinion as to whether a violation of this title has occurred or will occur. If the Board is unable to reach a determination based on the written submissions before it, the Board may schedule an informal conference to hear from the complainant, the public body, or any other person with relevant information about the subject of the complaint. An informal conference scheduled by the Board is not a contested case within the meaning of § 10–202(d) of the State Government Article. The Board shall issue a written opinion within 30 days after the informal conference. If the Board is unable to render an opinion on a complaint within the time periods specified in subsection (a) or (b) of this section, the Board shall: state in writing the reason for its inability to render an opinion; and issue an opinion as soon as possible but not later than 90 days after the filing of the complaint. An opinion of the Board may state that the Board is unable to resolve the complaint. The Board shall send a copy of the written opinion to the complainant and the affected public body.