Every insurance policy or contract shall contain a provision that it shall be incontestable after it has been in force during the lifetime of the insured for two years from its date of issuance, except for nonpayment of the policy’s assessments or premiums. In the case of life policies and at the option of the insurer, provisions relating to benefits in the event of disability and provisions which grant additional insurance specifically against death by accident or accidental means, may be excepted in the incontestability provision. This provision may be omitted if the time limit on the certain defense clause specified in § 38.2-3911 is included.