Which of the following taxpayers must file a federal income tax return? PICK ALL THAT APPLY!! An unmarried person qualifying as head of household with income of $20,000 A single non-dependent individual with income of $10,000 A single individual with income of $5,000 that is all from self-employment A married couple who are both over 65 with income of $27,000 a 20 year old dependent full time student with income of $2,000 all from investments