Suppose the tax rate on the first $10,000 income is 0 percent; 10 percent on the next $20,000; 20 percent on the next $20,000; 30 percent on the next $30,000; and 40 percent on any income over $80,000. family a has income of $40,000 and family b has income of $100,000. what is the marginal and average tax rate for each family? a. family a. marginallong dash—10 percent; averagelong dash—10 percent; family b. marginallong dash—30 percent; averagelong dash—30 percent. b. family a. marginallong dash—20 percent; averagelong dash—20 percent; family b. marginallong dash—40 percent; averagelong dash—40 percent. c. family a. marginallong dash—20 percent; averagelong dash—10 percent; family b. marginallong dash—40 percent; averagelong dash—23 percent. d. family a. marginallong dash—20 percent; averagelong dash—15 percent; family b. marginallong dash—40 percent; averagelong dash—20 percent.