What does the question "Was Roth IRA open on December 31, 2016?" mean?

You would answer Yes. The question is asking if you had any open or active accounts as of 12/31/2016. If you had money in a Roth account on that date, you would say Yes. 

The question is not asking if you opened any accounts during the year or placed money into a Roth during the year. That would be handled in the IRA contribution section. 

It is a very ambiguous question.

VERY confusing question for Michigan taxpayers who are attempting to remove a non-taxed Roth withdrawal entry from a Michigan state return