Before a question collects any responses, it can be edited. To do so, go to Question > Settings > Edit.
If I wanted to edit question xxxxxx, I would go to https://insightstore.civicscience.com/questions/xxxxxx/settings/edit (replace xxxxxx with the QID).
As shown above, the question and answer text can be edited. Answers can be added or removed. You can change many question options, including the classification.
After making the desired changes, click Update.