What is the word used to describe a question that demands one of two possible answers?
Politicians seem incapable of giving a straight answer when posed simple questions, sometimes because the question being asked simply cannot be dignified by a one word answer, other times because they are trying desperately to avoid revealing an ulterior motive or cock-up. But what do you call this kind of question?
For example:
Q: Is my t-shirt white or black? A: White
Q: Theresa, did you know about a reported failed Trident test when you addressed parliament during a debate on the renewal of Britain’s nuclear deterrent? A: Well, errr, I believe that..... strong and stable....
Solution 1:
Binary inherently means that there are only two options available (bi = two)
From the OED:
Binary
adjective
- Relating to, composed of, or involving two things.
- Relating to, using, or denoting a system of numerical notation that has 2 rather than 10 as a base.
A binary question therefore only has 2 possible answers.
There are similar terms for a different amount of answers. Ternary = 3 options to choose from. However, these are very rare. Ternary is only very rarely used; the others even less so.
HOWEVER
From context, you seem to mean "a question to which the answers are strictly defined and cannot be vague".
In this context, I would call it a clear-cut question.
Clear-cut
adjective
- Sharply defined; easy to perceive or understand.
‘we now had a clear-cut objective’
This doesn't inherently mean that there are two possible answers, but it does mean that the answers are very strictly defined and not up for discussion.
Solution 2:
Perhaps you're looking for a polar question?
In linguistics, a yes–no question, formally known as a polar question, is a question whose expected answer is either "yes" or "no". Formally, they present an exclusive disjunction, a pair of alternatives of which only one is acceptable.
There's lots more interesting info in the Wikipedia article.