of the action, OIRA shall complete the review. (B) Exception 45-day review If OIRA has previously reviewed the significant regulatory action described in subparagraph (A) and, since that review, there has been no material change in the facts and circumstances upon which the significant regulatory action is based, OIRA shall complete the review within 45 days after submission of the action. (5) Extension Any review described under this subsection may be extended for any number of additional 30-day periods upon mutual agreement of the Administrator and the head of the agency. For each 30-day extension, the Administrator shall make publicly available online a written explanation, including the reasons for the extension and an estimate of the expected conclusion date. (6) Return If the Administrator determines OIRA is unable to conclude a review within the time period described under this subsection, the Administrator may return the draft of the significant regulatory action to the agency with a written explanation of why OIRA was unable to complete the review and what additional information, resources, or time OIRA would need to complete the review. (7) Withdrawal An agency may withdraw the regulatory action from OIRA review at any time prior to the completion of the review. (e) Compliance review The Administrator shall review any significant regulatory action submitted under subsection (c) to determine the extent to which the agency— (1) identified the problem that the significant regulatory action is designed to address (including, where applicable, the failures of private markets or public institutions that warrant new agency action)