Where a member of the scheme who is a contributing member dies before retirement and is survived by a spouse, the spouse is entitled to a pension at a rate equal to five - eighths of the rate at which invalidity pay would have been payable to the deceased member if, on the date of the deceased member's death, the deceased member had become entitled to invalidity benefit and had been classified as Class A under section 30 and (in the case of a deceased member whose surcharge debt account is in debit when the pension becomes payable) had made an election under subsection 124(1).