Suppose that that the income tax in a certain nation is computed as a flat rate of 5 percent but no tax is levied above $50,000 in taxable income. taxable income in turn is computed as the individuals income minus $10,000 that is everyone gets a $10,000 deduction. What are the marginal and average tax rates for each of the following workers? A. a part time worker with annual income of $9,000 B. a retail sales person with an annual income of $45,000 C. an advertising executive with annual income of 4600,000 is the tax progressive, proportional, or regressive with respect to income?