A 19-year-old full-time college student is the son of divorced parents. He has lived with and been supported by his remarried mother and stepfather for the last 3 years. The stepfather has not adopted the stepson. In 2016 the mother dies. The stepfather continues to 100% support his stepson. What tax benefits are maintained or lost by the stepfather? Can the stepfather file a joint return with his deceased wife in 2016? Can the stepfather continue to claim the stepson as a dependent? What filing status may the stepfather use in 2017 and 2018, assuming he does not remarry? What filing status may the stepfather use in 2019?