The sum of the retirement allowances computed under (a) and (b) above may not be less than the allowance which would have been provided under (a) if all of the member's credited service were Class One service. For a police officer who became a member before July 1, 1974, and who was a participant in the Supplemental Allowance Program, the portion of his service retirement allowance not provided by his accumulated contributions may not be less than it would have been if the provisions of the System in effect on June 30, 1974, had continued in effect until his date of retirement.
S.C. Code § 9-11-60