A 4-day-old foal is presented with clinical signs of depression, icterus, head pressing, and disorientation. Serum biochemistry reveals increased levels of gamma-glutamyltransferase, alkaline phosphatase, and unconjugated bilirubin. On further questioning, the owner mentions that he gave the foal an oral nutritional supplement when it was a day old but was not sure what was in it. 'What could this supplement have contained to cause these clinical signs?

A - Vitamin E
B - Copper
C - Iron
D - Vitamin A
E - Selenium