Answer:
He is accused of being a heretic because of his beliefs.
Step-by-step explanation:
Martin Luther was a German professor who was widely known for his belief, which is contrary to the existing Christian principles at the time. By 1521, Martin Luther was condemned and excommunicated by Pope.
The reason was that at some point, Luther was challenged by Pope Leo X, at Roman Emperor Charles V during diet of worms. However, Luther shown his attitude by being defiant.
After his refusal to explain his wrtiting, he was eventually declared outlaw and herectic