https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-beneficiary#:~:text=If%20the%20inherited%20traditional%20IRA,out%20of%20the%20inherited%20IRA.
好像spouse 可以继承IRA,到限定的年龄开始withdraw,当成自己的IRA,在rollover 和withdraw 上 traditional or Roth 差别不大