Bob is a single individual and received a salary of $$27,000$ before he retired in October of this year. After he retired, he received Social Security benefits of $$3,000$ 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?