Which of the following tax systems could NOT be structured to satisfy conditions of vertical equity? A. proportional b. regressive c. progressive d. lumpsum Which tax system requires all taxpayers to pay the same percentage of their income in taxes? A. regressive b. proportional c. progressive d. horizontal equity Which tax system requires higher income taxpayers to pay a higher percentage of their income in taxes? A. progressive b. proportional c. regressive d. None of the above are correct. Which tax system requires higherincome taxpayers to have lower tax rates, even though they pay a larger amount of tax, than Lowerincome taxpayers? A. regressive b. progressive c. proportional d. None of the above are correct.