Which concerning characteristics or use of a Roth IRA is true? I. Contributions may NOT be made after the owner reaches their trigger year. II.Active participation in an employer's retirement plan restricts Roth IRA contribution eligibility. III. Withdrawals are tax-free regardless of the owner's age at withdrawal. IV. It is NOT subject to the required minimum distribution rules until the death of the plan holder. a.I & III b.III only c.II, III, & IV d.IV only