Each policy of group life insurance shall contain a provision that any sum due because of the death of the insured is payable to the beneficiary designated by the insured, subject to: the provisions of the policy as to payment of all or part of the sum if a designated beneficiary is not alive at the death of the insured; and any right that the insurer reserves in the policy and sets forth in the certificate to pay at its option a part of the sum, not exceeding $2,500, to a person that the insurer considers equitably entitled to it for having incurred funeral or other expenses incident to the insured’s death or last illness.