Question

What did Martin Luther post on a church door to publicly criticize the misuse of indulgences?

Answer 1

What Martin Luther posted on a church door to publicly criticize the misuse of indulgences were his A. ninety-five theses. In them, he profusely wrote about the flaws of the church and its ministers with the aim to change it radically. 
Reformation refers to the alteration of something, it's not a document. Ten Commandments are allegedly written by God himself. I don't see how D. is supposed to criticize anything.