What is the most expensive mandatory spending program for the federal government?
a.
medicare
b.
education
c.
social security
d.
public transportation

social security

Explanation:

Social Security is the single largest federal budget item, costing $1.151 trillion in FY 2021.1 The Social Security Act of 1935 guaranteed that workers would receive benefits after they retired. It was funded by payroll taxes that went into a trust fund used to pay out the benefits.

At first, there were more healthy workers paying into the fund than retirees taking benefits. This allowed Social Security to also provide training and funds to the blind and disabled in the Supplemental Security program.