There shall be a provision, with respect to benefits provided in the form of merchandise and services incident to the burial of the insured, that the policy shall be incontestable from its date of issue except for nonpayment of premiums and, with respect to benefits payable in cash, monuments, waiver of premium benefits and disability benefits, a provision that the policy shall be incontestable after it has been in force during the lifetime of the insured for a period of two years from its date of issue, except for nonpayment of premiums and except, at the option of the insurer, as to provisions relating to benefits in event of dismemberment or disability or to additional benefits for death by accident or accidental means.