(a) Notwithstanding any provision of this Act to the contrary, a public body shall respond to a request from a recurrent requester, as defined in subsection (g) of Section 2, within 21 business days after receipt. The response shall (i) provide to the requester an estimate of the time required by the public body to provide the records requested and an estimate of the fees to be charged, which the public body may require the person to pay in full before copying the requested documents, (ii) deny the request pursuant to one or more of the exemptions set out in this Act, (iii) notify the requester that the request is unduly burdensome and extend an opportunity to the requester to attempt to reduce the request to manageable proportions, or (iv) provide the records requested.
     (b) Within 5 business days after receiving a request from a recurrent requester, as defined in subsection (g) of Section 2, the public body shall notify the requester (i) that the public body is treating the request as a request under subsection (g) of Section 2, (ii) of the reasons why the public body is treating the request as a request under subsection (g) of Section 2, and (iii) that the public body will send an initial response within 21 business days after receipt in accordance with subsection (a) of this Section. The public body shall also notify the requester of the proposed responses that can be asserted pursuant to subsection (a) of this Section.
     (c) Unless the records are exempt from disclosure, a public body shall comply with a request within a reasonable period considering the size and complexity of the request.