Greg Earned $20,500 This Year and Had $1,500 of Federal

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:

A) is required to file a tax return.
B) is not required to file a tax return but should file a return anyway.
C) is required to file a tax return but should not file because he owes no tax.
D) is not required to file a tax return and should not file a return.
E) None of these.