mdk said
The only answer that makes sense is 0%, because it's consistent with its own odds of selection.
If you actually add that to the list of answers though, then the odds of selecting that answer is not 0%, meaning it's still a wrong answer.
If you wanted to add a correct answer, then you'd instead add 20%, because the odds of picking that answer would indeed be 20%. Which is way cooler.
Genuine question; would it be possible to have two distinct, but still correct answers for this question?