Connie and her spouse, Mark, (both over 65) are filing a joint return for 2022. They both received Social Security benefits during the year. In January 2022, Connie received a Form SSA-1099 showing net benefits of $7,500 in box 5. Mark received a Form SSA-1099 showing net benefits of $3,500 in box 5. Connie also received a taxable pension of $22,000 and interest income of $500. She did not have any tax-exempt interest income. What amount of Connie's Social Security benefits is taxable for 2022? 

A. $0 

B. $500 

C. $3,750 

D. $7,500