Therefore, D. his average tax rate is about 25%.
The average tax rate is computed as the total taxes paid or owed divided by the total taxable income, no matter the tax bracket.
Tax liability on a taxable income of $40,000 = $10,000
Tax liability on additional income of $1,000 = $280
Total tax liability = $10,280
Total taxable income = $41,000
Average tax rate = 25.7% ($10,280/$41,000 x 100).
Thus, John's average tax rate is about 25%.
Learn more about the average tax rate at https://brainly.com/question/8677433