All the following statements concerning contributions to a 401(k) plan are correct EXCEPT
A. A 401(k) plan can include employee after-tax contributions in addition to employee pre-tax salary deferrals.
B. A 401(k) plan can include a matching contribution feature in which the plan sponsor agrees to match employee salary deferrals to a certain extent.
C. If a plan has a profit-sharing feature; contributions are made only for eligible participants who make salary deferral contributions.
D. When a plan has more than just salary deferrals, it must have separate bookkeeping accounts for each type of contribution.