Mary is 2 years old, a dependent of her parents, and earned $ 10,000 in interest income on funds given to her by her grandparents. Mary's parents are in the 37% marginal income tax bracket, and her grandparents are in the 35% bracket. a. Calculate Mary's 2021 taxable income. b. Calculate Mary's 2021 federal income tax. c. Calculate Mary's 2021 federal income tax if the $ 10,000 were qualified dividend income instead of interest income