From H&R Block's 2015 tax software for Michigan:
Really? The best they could come up for that question is "Are you an unmarried spouse of a person who was 65 or older at the time of their death"?
An unmarried spouse?!
It took me a while to figure out that it means "Was your spouse 65 or older when they died, and do you remain unmarried?" At least I think that's what it means. No help/explanation anywhere.