Suppose there are three options: "A", "B", and "C", and two people each have to choose one of them. I want to say a sentence like the following:
"They both chose the same option".
As far as I know, "the" is the correct article. But it really bothers me. I am not specifying which option they chose (e.g. "B"), and it could be any of them ("A", "B", or "C"). So I would really like to use the phrase "a same option" to emphasize that we don't know which was chosen. What's the reasoning behind the "the" in this case?