I. Every taxpayer shall: (a) Keep such records as may be necessary to determine the amount of its liability under this chapter. (b) Preserve such records for the period of 3 years or until any litigation or prosecution under this chapter is finally determined. (c) Make such records available for inspection by the commissioner or authorized agents, upon demand, at reasonable times. II. Whoever violates the provisions of this section shall be subject to the penalties imposed under RSA 21-J:39.