15-31-405. Information return -- period for assessment of tax. When a corporation formerly subject to tax under part 1 of this chapter becomes subject to tax under this part, it shall file an information return for the income year in which the change occurs. The tax for the year in which the change occurs will be assessed under parts 1, 3, and 5 and not under this part. For years subsequent to the year in which the change occurs, the tax will be assessed under this part.