for the granting of a fair hearing and a prompt determination thereafter to any household aggrieved by the action of the State agency under any provision of its plan of operation as it affects the participation of such household in the supplemental nutrition assistance program or by a claim against the household for an overissuance: Provided , That any household which timely requests such a fair hearing after receiving individual notice of agency action reducing or terminating its benefits within the household’s certification period shall continue to participate and receive benefits on the basis authorized immediately prior to the notice of adverse action until such time as the fair hearing is completed and an adverse decision rendered or until such time as the household’s certification period terminates, whichever occurs earlier, except that in any case in which the State agency receives from the household a written statement containing information that clearly requires a reduction or termination of the household’s benefits, the State agency may act immediately to reduce or terminate the household’s benefits and may provide notice of its action to the household as late as the date on which the action becomes effective. At the option of a State, at any time prior to a fair hearing determination under this paragraph, a household may withdraw, orally or in writing, a request by the household for the fair hearing. If the withdrawal request is an oral request, the State agency shall provide a written notice to the household confirming the withdrawal request and providing the household with an opportunity to request a hearing;