You receive a paycheck from your employer, and your pay stub indicates that $$400$ was deducted to pay the FICA $($Social Security$/$Medicare$)$ tax. Which of the following statements is correct?

a$.$ This type of tax is an example of a payback tax.

b$.$ Your employer is required by law to pay $$400$ to match the $$400$ deducted from your check.

c$.$ The $$400$ that you paid is the true burden of the tax that falls on you, the employee.

d$.$ All of the above are correct.