Indicate, in each of the following situations, the number of exemptions the taxpayers are entitled to claim on their 2010 income tax returns. a. Donna, a 20-year-old single taxpayer, supports her mother, who lives in her own home Her mother has income of $1,350. b. William, age 43, and Mary, age 45, are married and support William's 19-year-old sister, who is not a student. The sister's income from a part-time job is $3,700. c. Devi was divorced in 2010 and receives child support of $250 per month from her ex-husband for the support of their 8-year-old son, John, who lives with her. Devi is 45 and provides more than half of her son's support