a. Reginald, a U.S. citizen and resident, contributes 100% of the support of his parents who are citizens of Canada and live there. b. Pablo, a U.S. citizen and resident, contributes 100% of the support of his parents who are citizens of Panama. Pablo's father is a resident of Panama, and his mother is a legal resident of the United States. c. Gretchen, a U.S. citizen and resident, contributes 100% of the support of her parents who are U.S. citizens but residents of Germany. d. Elena is a U.S. citizen and a resident of Italy. Her household includes Carlos, a four-year-old adopted son who is a citizen of 5 pain