Calculate the 2021 total "child tax credit and other dependent credit" for the following taxpayers. Please explain how you arrived at your answer. a. Nancy is a single mother with 6-year-old and 11-year-old dependent sons and has $50,000 of AGI. b. Susan and Mel have one dependent 12-year-old child and $426,300 of AGI. c. Kathy is single and has one dependent 28-year-old son and $21,000 of AGI. Answer: 10