Benefits for policies issued under these regulations shall be deemed reasonable in relation to premiums if claims incurred under the policies result in, or may reasonably be expected to result in, a loss ratio of not less than 55 percent when premiums do not exceed prima facie premium rates. When the prima facie loss ratio exceeds 58 percent, the premiums shall be determined in accordance with the methods of Regulation .12 of this chapter. Rate Reduction. When the prima facie loss ratio is less than 52 percent: A reduced premium rate shall be used that is calculated by dividing the prima facie loss ratio by 0.55 and multiplying the result by the prima facie premium rate; but Except as provided in §C(2) of this regulation, the reduced premium rate may not be less than 40 percent of the prima facie premium rate. At the option of the insurer, a premium rate less than 40 percent of the prima facie premium rate may be used.