Wright Corporation's taxable income for calendar years 2015, 2016, and 2017 was $120,000, $150,000, and $100,000, respectively. Its total tax liability for 2017 was $22,250 (under the tax rates in effect that year). Wright estimates that its 2018 taxable income will be $600,000, on which it will owe federal income taxes of $126,000. Assume Wright earns its 2018 taxable income evenly throughout the year.

a. What are Wright's minimum quarterly estimated tax payments for 2018 to avoid an underpayment penalry?

b. When is Wright's 2018 tax return due?

c. When are any remaining taxes due? What amount of taxes are due when Wright files its return assuming it timely paid estimated tax payments equal to the amount determined in Part a?

d. How would your answer to Part a change if Wright's tax liability for 2017 had been $200,000?