Nan's salary in 2020 is $40,000. Nan elects to defer 5% of her salary into her employer's 401(k) plan. Her employer provides a matching contribution on the first 4% contributed. What is the net impact on Nan's 2020 taxable income from these items?

a.$40,000

b.$41,600

c.$38,000

d.$39,600

e.None of these choices are correct.