(a) If so provided in its charter, a domestic stock or domestic mutual insurer may issue any or all of its policies with or without participation in profits, savings, or unabsorbed portions of premiums, may classify policies issued on a participating or nonparticipating basis, and may determine the right to participate and the extent of participation of any class or classes of policies. Any classification or determination shall be reasonable and shall not unfairly discriminate as between policyholders within the same classification.
(b) No dividend, otherwise earned, shall be made contingent upon the payment of a renewal premium on any policy.