Sorry of this has been brought up before.
I think by the addition of an extra text box to each question answer we can create a very powerful learning experience for students.
At the end of the exam during the review it would be very useful if an explanation of why an answer is correct or incorrect could be given. That explanation only requires the addition of an extra field alongside each of the question answers. This information would help the students to understand why the question is incorrect rather than it was just the wrong answer.
I believe Moodle has a similar feedback feature.
Many thanks for a great plugin,
