Chris baker's adjusted gross income on her current year tax return was $160,000. the amount covered a 12-month period. for the next tax year, baker may avoid the penalty for the underpayment of estimated tax if the timely estimated tax payments equal the required annual amount of: . 90% of the tax on the return for the current year paid in four equal installments. ii.110% of prior year's tax liability paid in four equal installments. a. i only. b. both i and ii. c. ii only. d. neither i nor ii.