to support adding images in multiple choice answers
1. It is the trend to use images in learning.
2. Many school subjects, such as physics, chemistry, biology, geography, and even math would have high chances of having images in multiple choice answers (in math, a graphic form of x^2 should be much better when presenting in answer field).
3. Without the support of images in answer field, many good assessing questions would be unable to use. The system would look inferior to hard copy version.