Which of the following is not true about FICA taxes?

a. The FICA tax has two parts, Social Security (Old Age, Survivors, and Disability Insurance) and Medicare.
b. In 2016, the maximum wage base for Social Security tax withholding is $117,000.
c. In 2016, there is no maximum wage base for Medicare tax withholding.
d. When employees work for more than one employer and exceed the maximum wage base for Social Security tax withholding in total, they are allowed a refund of excess tax withheld.