1. If you want to add a new category, you must submit the first quiz question in that category.
2. Click on the create new quiz question link.
3. Enter your quiz question for this new category.
4. At the bottom of the 'Create Quiz' page, click on the new category ... link.
5. Type in the name of your new category.
6. Submit the quiz question.
7. After a day or two, the new category will be added - with your quiz question in it.