"Where did he go yesterday?"
Translation:Ble aeth e ddoe?
It's always interesting to learn these things, but I'm not sure that the best way to introduce them is via the multiple-choice questions. It has happened to me a few times as well and it often comes down to pure guess-work. Plus, from the app it is then more difficult to raise a question in the discussions.
I have a sneaking suspicion that the multiple-choice answers may get chosen randomly from the list of valid answers. If that is the case this will get worse as more and more dialects and variations are added as acceptable answers. That could lead to some really bizarre questions and answers.
If the multi-choice questions are created entirely manually, then it seems an odd option to put when it has had no prior introduction or explanation.
The multiple choice questions are generated randomly, as you surmise from the 'correct answers' we have provided. In our inexperience we have sometimes put too many options in the correct answer line instead of restricting it to one or at most two options, we're working to correct this at present. Please report it in the course or list the unit and question here. Diolch.