Which of the following statements is/are correct when applied to both qualified and nonqualified plans? I. The plan generally is established to provide retirement benefits. II. The employer is entitled to a deduction in the year a contribution to the plan is made. III. The employee is taxed on plan benefits in the year that the contributions are made. IV. The plan must be offered to all employees who are age 21 and have one year of service. I only II only I and II only I, III, and IV only