A nonresident alien in which of the following situations is required to file an income tax returnb, Form 1040NR, or Form 1040NR-EZ a. Unable to leave the U.S. due to a medical condition. B. Engaged in a trade or business in the U.S. during the tax year C. received a Form 1042-S reporting gambling winnings, upon which 30% was withhelf for taxes D. Received Form 1042-S from U.S. employer for wages paid and taxes withheld.