Greg earned $20,500 this year and had $1,500 of federal income taxes withheld from his salary. Assuming that Greg will have a total tax liability of $1,000 (and thus will receive a $500) refund, he: is required to file a tax return. is not required to file a tax return but should file a return anyway. is required to file a tax return but should not file because he owes no tax. is not required to file a tax return and should not file a return. None of the above