Final answer:
Federal law requires employers to match employees' Social Security contributions deducted from their paychecks.
Step-by-step explanation:
The total amount deducted from employees' paychecks that federal law requires employers to match is Social Security contributions (option A).
Under federal law, employees contribute 6.2% of their wages for Social Security, and employers are required to match this amount with an additional 6.2% contribution.
It is important to note that although employees only see the deduction of 6.2% from their paycheck, economists argue that the employer's share of the taxes is passed along to the employees in the form of lower wages, meaning that in reality, the worker pays the full amount of payroll taxes.