Paul, age 37, participates in a Section 401(k) plan which allows employees to contribute up to 15 percent of their salary. His annual salary is $125,000 in 2019.

What is the maximum he can contribute, on a tax-deferred basis under a salary reduction agreement, to this plan?

a. $24,000

b. $20,500

c. $18,500

d. $18,000

e. None of the above