89.2. A taxpayer who, in a taxation year ending after 31 December 1973, receives a payment described in subparagraph i or iv of paragraph a of section 345 of the Taxation Act (chapter I-3) in respect of which the taxpayer would be entitled to invoke section 44 of the former Tax Act respecting individuals if that Act and the provisions to which that section refers were still in force, may elect to compute the taxpayer’s tax payable for the taxation year concerned by applying, with the necessary modifications, the method provided for in that section 44, but only up to the amount of the part of the payment that corresponds to the amount the taxpayer would have received under the retirement plan or deferred profit sharing plan if the taxpayer had withdrawn from the plan on 1 January 1972 and if there had been no change in the terms and conditions of the plan after 18 June 1971 and before 2 January 1972. Where any tax is payable under the first paragraph in addition to or in lieu of any amount of tax payable under Part I of the Taxation Act for a taxation year, the tax payable under that paragraph is deemed to be payable under Part I of the Taxation Act for the taxation year.