There shall be a provision in participating policies that, beginning not later than the end of the third policy year, the insurer shall annually ascertain and apportion the divisible surplus, if any, that will accrue on the policy anniversary or other dividend date specified in the policy provided the policy is in force and all premiums to that date are paid. Except as hereinafter provided, any dividend so apportioned shall at the option of the party entitled to elect such option be either (a) payable in cash or (b) applied to any one of such other dividend options as may be provided by the policy. If any such other dividend options are provided, the policy shall further state which option shall be automatically effective if such party shall not have elected some other option. If the policy specifies a period within which such other dividend option may be elected, such period shall be not less than thirty days following the date on which such dividend is due and payable. The annually apportioned dividend shall be deemed to be payable in cash within the meaning of (a) above even though the policy provides that payment of such dividend is to be deferred for a specified period, provided such period does not exceed six years from the date of apportionment and that interest will be added to such dividend at a specified rate. If a participating policy provides that the benefit under any paid-up nonforfeiture provision is to be participating, it may provide that any divisible surplus apportioned while the insurance is in force under such nonforfeiture provision shall be applied in the manner set forth in the policy.