Answer: I would go with B.
Explanation: The group of words for option B seem like they would be used more for contrasting than option D. It can't be option A or option C because those options use comparing signal words.
Lake and huge mirror are compared in number 1
What is a recurring concept in this excerpt is E. the thirst for knowledge and new experiences.
As you can see in this excerpt, the narrator says that even though he has attained a lot of experience throughout his life, whenever he thinks about 'tat untravell'd world,' he gets a desire to move again and explore more. He thinks that there is so much that he hasn't seen yet, and with his life slowly withering away, he wants to make use of that little time he has left to learn and explore more.