Answer:
a. German.
Step-by-step explanation:
When the Social Security Act was passed in 1935, the United States followed the German model by selecting 65 as the age of eligibility for retirement benefits. The German model, established in the late 1800s, provided for a retirement system in which workers and employers contributed to a fund that provided retirement benefits for workers starting at age 65. This model influenced the development of retirement programs in many other countries, including the United States.