There are several things I don't like with how options disappear with multiple choice questions:
- It often starts before I had time to think a bit, and read all answers. Partly because my hiragana reading isn't too fast. Generally I think the time limit for this question type is rather short, especially compared to how much time I have for typing questions.
- The graphical effect of disappearing is too attention drawing. Perhaps use a darker shade of gray.
- Removed panels are skipped in keyboard navigation. Makes it pretty hard to reliably navigate to a certain answer, especially if a panel disappears while I'm navigating.