The Posting Heard Round the World

Five hundred years before a post on a blog could have national and global impact,
Martin Luther made a primitive posting on a door. The Church has been reeling from
this event’s consequences ever since.

Recently, someone suggested to me that Luther was only asked by the pope to recant
48 of his 95 theses. Does anybody know if this is true? If so, which theses were
acceptable and which were not? I wonder how events might have played out if Luther
had chosen to be less defiant.