Compute the child tax credit for each of the following taxpayers. a. Jett is married but does not file a joint return with his spouse. Jett claims his six-year-old son as a dependent and files as head of household under the abandoned spouse rules. Jett's AGI is $85,440. b. Eren is divorced. She and her ex-husband share custody of their four children, ages 2-8, but Eren is the custodial parent. She has not signed away her right to claim the children as dependents. She files as a head of household. Her AGI is $95,694. c. Michelle is 43 years old and a single parent. She claims her three children, ages 9, 14 and 17, as dependents. She files as a head of household. Her AGI is $123,639. d. Randy and Tammy O'Brien file a joint return. Tammy's 16-year-old sister lives with them the entire year. They claim the sister and their two-year-old daughter as dependents. The O'Briens AGI is $145,800.