Bob is a single individual and received a salary of $27,000 before he retired in October of this year. After he retired, he received Social Security benefits of $3,300 during the year. A. What amount, if any, of the Social Security benefits are taxable to Bob for the year? B. Would the answer be different if Bob also had $1,000 of tax-exempt interest for the year? C. What if he had $20,000 of tax-exempt interest for the year?