Which of the following distributions is eligible for rollover treatment?

A 55-year-old surviving spouse's distribution from a 60-year-old decedent's qualified plan. The decedent was employed at the time of death.

A distribution of excess deferrals made to a taxpayer because they were a highly-compensated employee who unknowingly paid too much into their employer's qualified plan.

A hardship distribution. By the time the distribution was received, the taxpayer no longer faced the hardship.

A required minimum distribution (RMD) from a 73-year-old taxpayer's former employer's qualified plan. The taxpayer continues to work and is an active participant in his current employer's qualified plan.