The correct option is B. The source of information, that would offer the most reliable fact-based information about the author is a book, that is written by the author himself. This type of source is called primary source. Information obtained from Wikipedia, movie and books published by other authors can only offer secondary information, which are not as reliable as information from primary source.
In this excerpt from "Sir Gawain and the Green Knight," we can see that everyone was scared of the skin colour of the Knight. So much that they though he might have been a ghost.
So, when the green Knight spoke, nobody could answer him, not even the noble Knights, who were petrified.
