Final answer:
Employers must maintain separate accounts for each employee with a defined contribution plan, where both employer and employee make regular contributions that the employee invests. These plans offer tax-deferred growth, portability, and protection from inflation.
Step-by-step explanation:
The question refers to the type of retirement plan employers must maintain separate accounts for each employee. The correct answer is a) Contribution, which correlates with a defined contribution plan. In this setup, employers contribute a fixed amount to the employee's retirement account regularly, which is often matched by the employee's contributions. These funds are invested in various investment vehicles, offering tax-deferred growth and the advantage of being portable across different employers. The plan's value is dependent on the investment's performance, thus shielding retirees from the mounting costs attributed to inflation, in contrast to traditional pensioners under the defined benefits retirement plans. Additionally, employers offering pensions are obliged to pay into the Pension Benefit Guarantee Corporation as insurance to safeguard at least some pension benefits in the event of bankruptcy.