In 1566 protestant iconoclasts threatened to destroy van eyck's

It was the Ghent Altarpiece. This was a considered as a symbol of medieval art advancement.  The outer frame of the Altarpiece before had a clock and believed to play music but was destroyed during the days of Reformation. It also has an inscription of Ivan's name which points out that he was the first artist that started that altarpiece.

I think D

Explanation: