What were the ratios of workers paying into Social Security to retirees receiving benefits for 1950 and 2009, respectively?
a. 1950: 16.5 to 1 2009: 3 to 1
b. 1950: 8.5 to 1 2009: 8 to 1
c. 1950: 10.5 to 1 2009: 6 to 1
d. 1950: 6.5 to 1 2009: 10 to 1
e. 1950: 3.5 to 1 2009: 16 to 1