Subject to subsection (b) of this section, the adopting authority for each unit shall every 8 years, beginning on or after October 1, 2001, submit to the Governor and to the Committee a schedule of regulations to be reviewed under this part during the following 8 years. To the extent possible and reasonable, an adopting authority shall schedule related regulations to be reviewed concurrently. Unless good cause exists for publishing a larger group of regulations concurrently, the largest group of regulations that an adopting authority may schedule for review concurrently shall be a subtitle. At the time that a unit’s regulations are scheduled for review under this part, an adopting authority may certify to the Committee and the Governor that the review of a regulation or group of related regulations would not be effective or cost-effective and is exempt from the review process under this subtitle because the regulation or group of related regulations was: adopted to implement a federally mandated or federally approved program; or initially adopted or comprehensively amended during the preceding 8 years. An adopting authority issuing a certificate of exemption shall provide the Governor and Committee with written justification for the certificate of exemption. If there is more than one adopting authority for a regulation or group of related regulations for which an exemption is to be certified, each adopting authority shall sign the certificate of exemption and written justification required under this subsection. At any time during a review cycle, the Governor or Committee may ask that an adopting authority review a regulation or group of regulations for which a certificate of exemption has been issued, notwithstanding the claim of exemption.