Mr. and Mrs. Tsayong are both over 66 years of age and are filing a joint return. Their income this year consisted of the following: Taxable interest income Taxable pension Total Social Security benefits Tax - exempt interest $10,000 16,000 20,000 5,000 They did not have any adjustments to income. What amount of Mr. and Mrs. Tsayong's Social Security benefits is taxable this year? A. $4,500 B. $20,000 C. $0 D. $10,000