15-30-2113. Determination of marital status. For purposes of this chapter:
(1) the determination of whether an individual is married must be made as of the close of the individual's tax year, except that if the individual's spouse dies during the individual's tax year, the determination must be made as of the time of death; and
(2) an individual legally separated from the individual's spouse under a decree of divorce or of separate maintenance may not be considered as married.