The Planning Board shall, within 45 days after its meeting at which the application for final site plan approval is filed, approve the final site plan as submitted, approve it subject to conditions, modifications or other requirements which the Board shall specify or disapprove it by resolution for reasons which the Board shall specify, in each case advising the applicant, in writing, of the decision made and, if applicable, the conditions, modifications or other requirements specified or the reasons for disapproval. The determination of the Planning Board shall be deemed a final determination. If the Board shall fail to state its determination within 45 days after the filing of the application, then, unless the time has been extended by written consent of the applicant, the final site plan, as submitted, shall be deemed approved by the Planning Board.