When Lisa lost her job, she had an account balance of $25,000 in her 401(k). She also had an outstanding 401(k) plan loan of $9,000 secured by that balance. She made no after-tax contributions. If Lisa is unable to repay the loan and elects to take it as a distribution, what is the mandatory withholding?

a) $1,800

b) $3,200

c) $5,000

d) $6,800