A taxpayer with AGI of $170,000 in both 2016 and 2017 can avoid the underpayment penalty in 2017 by making sure that his withholding or estimated tax payments are at least: O 90% of 2016 tax liability 100% of 2016 tax liability O 105% of 2016 tax liability O 110% of 2016 tax liability Question 3 Paying 100% of the prior year's tax liability to avoid an underpayment penalty only works when a taxpayer's prior year's AGI does not exceed O $150,000 O $100,000 O $200,000 O $125,000