(a) Where the beneficiaries for the death benefit and the disability retirement option are the same, the Retirement System shall perform the comparison described in subdivision c, above, except that the annual option payment shall be multiplied by the appropriate factor and the lump sums shall be compared.

(b) Where the beneficiary(ies) of ordinary death benefits payable under section 60 or section 360 is (are) different from the beneficiary(ies) under Chapter 710, the disability retirement shall be deemed effective on the date prior to death, as provided under Chapter 710 of the Laws of 1989.