I would go with B, becuz in most stories they use rainy days to create sad mood
The third one. A person uses another's lack of knowledge as proof his argument is correct.
This may be helpful:
https://literarydevices.net/fallacy/
Rhetoric is the art of discourse, an art that aims to improve the capability of writers or speakers to inform, most likely to persuade, or motivate particular audiences in specific situations. As a subject of formal study and a productive civic practice, rhetoric has played a central role in the European tradition.<span>Its best known definition comes from </span>Aristotle, who considers it a counterpart of both logic and politics, and calls it "the faculty of observing in any given case the available means of persuasion<span>."</span>
Answer:
I think it would be "But before long these specimens began to seem less valuable." It should be this quote, because it lets the reader know that there is going to be a shift in the story.