(a) Reserves for policies and contracts issued prior to March 13, 1978, may be calculated, at the option of the company, according to any standards that produce greater aggregate reserves for all such policies and contracts than the minimum reserves required by the laws in effect immediately prior to March 13, 1978.

(b) Reserves for any category of policies, contracts or benefits established by the commissioner, issued on or after March 13, 1978, may be calculated, at the option of the company, according to any standards that produce greater aggregate reserves for the category than those calculated according to the minimum standard provided in this part, but the rate or rates of interest used for policies and contracts, other than annuity and pure endowment contracts, shall not be greater than the corresponding rate or rates of interest used in calculating any nonforfeiture benefits provided in the policies or contracts.

(c) A company, which adopts at any time a standard of valuation producing greater aggregate reserves than those calculated according to the minimum standard provided under this part may adopt a lower standard of valuation with the approval of the commissioner, but not lower than the minimum provided herein; provided that, for the purposes of this section, the holding of additional reserves previously determined by the appointed actuary to be necessary to render the opinion required by § 56-1-903 shall not be deemed to be the adoption of a higher standard of valuation.