Any member of the fire department who completes at least twenty-five (25) years of service in the aggregate and attains the age of fifty (50) years, said service to be computed under Section 8.585-10, may retire for service at his or her option. A member retired after meeting the service and age requirements in the sentence next preceding, shall receive a retirement allowance equal to fifty-five (55) percent of the final compensation of said member, as defined in Section 8.585-1, plus an allowance at the rate of four percent of said final compensation, for each year of service rendered in excess of twenty-five (25) years; provided, however, that such retirement allowance shall not exceed seventy-five (75) percent of said member's final compensation. A member retired after attaining the age of sixty-five (65) years, but before completing twenty-five (25) years of service in the aggregate computed under Section 8.585-10, shall receive a retirement allowance which bears the same ratio to fifty (50) percent of the final compensation of said member, as defined in Section 8.585-1, as the service with which he or she is entitled to be credited, bears to twenty-five (25) years. If, at the date of retirement for service, or retirement for disability resulting from an injury received in performance of duty, said member has no spouse, children or dependent parents, who would qualify for the continuance of the allowance after the death of said member, or with respect to the portion of the allowance which would not be continued regardless of dependents, or upon retirement for disability resulting from other causes, with respect to all of the allowance and regardless of dependents at retirement, a member retired under this section, or Section 8.585-3, may elect before the first payment of the retirement allowance is made, to receive the actuarial equivalent of his or her allowance or the portion which would not be continued regardless of dependents, as the case may be, partly in a lesser allowance to be received by him or her throughout his or her life, and partly in other benefits payable after his or her death to another person or persons, provided that such election shall be subject to all the conditions prescribed by the Board of Supervisors to govern similar election by other members of the Retirement System, including the character and amount of such other benefits.