Luc, a single taxpayer, earns $150,500 of taxable income during the current year. He also has $36,000 in city of Wheeling bonds. If Luc earned an additional $62,000 of taxable income this year and was interested in knowing the tax rate that applies to this extra income, which tax rate would he compute? O a. The effective tax rate. O b. The average tax rate. O c. The marginal tax rate. Od. The proportional tax rate.