This option provides payment to the pensioner for life. In the event the pensioner dies within five years of retirement, benefits shall continue in the same amount to a beneficiary the pensioner shall have designated for the balance of such five year period. The pensioner may change the designated beneficiary at any time prior to his death by filing a new designation of beneficiary form with the Comptroller. The beneficiary of a pensioner shall not be eligible for a lump sum payment of the benefit. In the event the pensioner shall have designated his estate as beneficiary, or if his designated beneficiary(ies) shall have predeceased him, or if he has failed to designate a beneficiary, the commuted value of the remaining payments, if any, for the balance of the five year period shall be paid in a lump sum to the pensioner's estate or in accordance with the provisions of section 1310 of the Surrogate's Court Procedure Act.