Determine whether or not the situation describes a function. Give a reason for your answer.

The amount of federal income tax you pay is a function of your taxable income.
a.
No, it is not a function. For a specific income, you pay only one tax amount.
b.
Yes, it is a function. At the end of the year, you will have two different tax amounts.
c.
No, it is not a function. Every year, you pay a different amount of tax.
d.
Yes, it is a function. For a specific taxable income at the end of the year, you will pay only one income tax amount.