93. The pension plan may permit a member or the spouse of a member who has become entitled to a pension to elect, before payment of the pension begins, to replace all or part of the pension
(1) by a pension the amount of which is adjusted to take into account an amount equal to the benefits determined under the Old Age Security Act (Revised Statutes of Canada, 1985, chapter O-9), the Act respecting the Québec Pension Plan (chapter R-9) or a similar plan within the meaning of paragraph u of section 1 of the latter Act;
(2) by a pension the amount of which is adjusted periodically according to an index or at a rate provided in the plan;
(3) by a pension the amount of which is adjusted by reason of provisions relating to the payment of benefits payable after the death of the member or his spouse, or by reason of amendments to such provisions; unless the spouse consents thereto, the spouse’s pension which results from this election shall not be less than the pension to which he would have been entitled under section 87;
(4) by a single payment or a series of payments in the event of a physical or mental disability that reduces life expectancy;
(5) if the value of the pension is less than 4 % of the Maximum Pensionable Earnings established under the Act respecting the Québec Pension Plan in respect of the year in which he became entitled to the pension, by a lump sum payment;
(6) by other benefits prescribed by regulation.