John milton's paradise lost was written before he became blind explores the mysteries of heaven and hell is autobiographical is considered a sub-par attempt at epic-writing

The correct answer is "explores the mysteries of heaven and hell"

Milton claimed that his role in writing the epic was to explain the ways of God to men. When he wrote it, he was completely blind, and even though there are some autobiographical elements it is not considered to be an autobiographical work. It is far from sub-par, as it is one of the most important epics in the history of world literature.