The case of Bronze Diabetes - solution
The answer: choice number "3." Jason had lost his bronze colour because of monthly blood letting.
Jason had an unusual form of diabetes. His diabetes was caused by excess iron in his body. The excess iron damages the pancreas and causes diabetes. It also leads to increased skin pigmentation and hence the name "bronze diabetes." The underlying disease is called hemochromatosis. If I see a person with Type 2 diabetes who has increased skin pigmentation I routinely check for excess iron. This can be done a few ways one of which is doing a blood test to check iron levels. If you want to find out more about hemochromatosis this link is a good starting point.
By the way, this is the format I use in my book (What Your Doctor Really Thinks).
Old cases of the month can be found here.