Every executor or administrator shall:
I. Keep such records as may be necessary to determine the amount of liability for tax under this chapter.
II. Preserve such records for a period of 3 years after the returns required by this chapter have been filed or until any litigation or prosecution under this chapter is finally determined, whichever is later.
III. Make such records available for inspection by the commissioner or the commissioner's authorized agents, upon demand, at reasonable times during regular business hours. Whoever violates the provisions of this section shall be subject to the penalties provided in RSA 21-J for such actions.