Diane and Amanda, who are 28-year-old twins, are partners in a computer software consulting firm with 20 employees. The average age of their employees is 25 and their length of employment averages three years. The firm is profitable and enjoys stable cash flows. Diane and Amanda have talked about a retirement plan as an employee benefit and do not want to assume the investment risk of the plan. The partners do wish to encourage employees to make elective deferrals. Of the following retirement plan options, which is best suited for their business?

A. A Section 403(b) plan

B. A stock bonus plan

C. An eligible Section 457 plan

D. A profit-sharing plan with a Section 401(k) provision