The dialogue shows that Furtunato thinks Montrsor is playing a joke on him.
This question seems to be incomplete. However, there´s enough information to find the right answer.
Answer: Dorian was the son of Lady Margaret Devereux. His mother was a glamorous high-class woman that had gotten married to Dorian´s father against her own father´s wishes. Lord Kelso, her father, disliked that she had married below her class, so he hired someone to provoke Dorian's father into a duel that has him killed. Margaret dies soon after she goes back to live with Kelso and Dorian ends up being raised by his grandfather, despite their mutual dislike for each other.
Explanation:
Dorian is the main character from Oscar Wilde´s "The Picture of Dorian Gray" (1890).
b) to mountain-bike
since the sentence follows along with to run and to swim the answer has to be "to mountain-bike".
I would say that the best theme to address those key points listed, would be: A. Feeling hopeless is unreasonable when faced with challenges. In other words, we shouldn't feel as if the end of that world is at hand, just because challenges and tests come our way. That is to be expected. Hope that helps.