A. a pay-as-you-go approach is the foundation of Social Security.
B. the foundation of Social Security is a pay-as-you-go approach
C. the approach of Social Security is pay-as-you-go
D. Social Security's approach is pay-as-you-go
E. Social Security is founded on a pay-as-you-go approach
Ans. E
How do you know "Social Security" is system, but not "pay-as-you-go"?
