Answer:
C. an average rate, regardless of the level of income
Step-by-step explanation:
The average tax rate is the proportion of tax over total income that a person pays.
A proportional income tax applies the same rate for all people, regarless of income.
For example, if the proportional income tax rate is 15%, the person who made $100,000 dollars in a year pays $15,000 because $100,000 x 15% = $15,000.
And the person who made $30,000 in a year pays $4,500 in taxes because $30,000 x 15% = $4,500.
Proportional income taxes are regressive because they place a higher tax burden on lower earners. People who make less money, but still have to pay tax, are left with even less income, and this can lead them into poverty if they are not poor already.