The table illustrates the income tax rates for citizens of country x. the tax code includes no allowable deductions or exemptions, and all citizens are required to file individual tax returns. what type of tax is country x's income tax?

group of answer choices

it is a progressive tax because high-income citizens are taxed at a higher rate than low-income citizens.

it is a proportional tax because high-income citizens pay a larger proportion of their income than low-income citizens.

it is a flat tax because the rate of increase in the tax rate is the same between each income tax bracket.

it is a regressive tax because low-income citizens are taxed at a lower rate than high-income citizens.