So a noun clause is a dependent clause that acts as a noun. Noun clauses begin with words such as how, that, what, whatever, when, where, whether, which, whichever, who, whoever, whom, whomever, and why. Noun clauses can act as subjects, direct objects, indirect objects, predicate nominatives, or objects of a preposition.
<u>Answer:</u>
"It's rather a mystery--" provides evidence that Whitney is a more sensitive person than Rainsford.
<u>Explanation:</u>
When Whitney expresses his view on the dank tropical island as “It’s rather a mystery--” explains that he is more sensitive than Rainford. Because, Whitney expressed his views upon the island fearfully where Rainford was trying to fear Whitney by saying dark things about Island and how sailors perceive that place to Whitney which makes him even more dreadful. But from the given context explains that Whitney is kind.
Obsess for the first one and hoax for the second... hopes this helps!
The answer is would be A.