A. The board of trustees shall award disability benefits to eligible members who have been officially certified as having a disability by the State Medical Disability Board. The disability benefit shall be the lesser of (1) or (2) as set forth below:
(1) A sum equal to the greater of forty-five percent of final average compensation or the member's accrued retirement benefit at the time of termination of employment due to disability; or
(2) The retirement benefit which would be payable assuming accrued creditable service plus additional accrued service, if any, to the earliest normal retirement age based on final average compensation at the time of termination of employment due to disability.
B. Upon approval for disability benefits, the member shall exercise an optional retirement allowance as provided in R.S. 11:1423 and no change in the option selected shall be permitted after it has been filed with the board. The retirement option factors shall be the same as those utilized for regular retirement based on the age of the retiree and that of the spouse, had the retiree continued in active service until the earliest normal retirement date.