The person to whom the whole or any part of a death benefit is payable may, at any time before payment thereof, elect in writing to have such death benefit or part thereof paid over a period not to exceed 10 years in monthly installments, plus interest on the unpaid balance thereof, at a rate to be determined by the board. If such person dies before all such installments are paid, the board shall pay the balance in one lump sum to his estate or person entitled to receive his property.