Create a "model solution" feature. This feature should allow instructors to provide a model solution (sample answer) to students.

Solution format -- instructor should be allowed to provide the solution (as per other tools) as
- inline text
- formatted (HTML/XHTML) text
- attachment(s)

Solution release.

The instructor should be able to automatically release the submission on an individual and class/section-wide basis.

1. A selectable time (hours, days) after the student has made a submission
2. After the instructor has graded the assignment
3. A selectable time (hours, days) before or after the "accept until date"

The instructor should be allowed to allow a logical combination of all three criteria (e.g. release model solution) that makes semantic sense.

Examples:
- release model solution 1 day after the student has submitted the assignment
OR immediately (0 hours, minutes, days) after the instructor has graded the student's submission.
- release model solution to each student one hour after the "accept until date" AND the student has made a submission (to prevent release of the model solution for late submissions).