I believe the answer is A.) However because it is used to show how petroleum is different than coal which is a contrast.
C: Because he made significant discoveries about electricity,
It can be said that chivalry affected the characters when the Knights exhibited their behavior. The Green Knight challenged the knights´honor and so Sir Gawain asked the King to accept that challenge. It seems that he wanted to show his loyalty (value of Chivalry) to King Arthur. Later on, the Green Knight promised to keep his word (value of Chivalry).
Answer:
A. "The king and his court were in their places, opposite the twin doors, <u>those fateful portals</u>."
